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651- 3m-

[GWCTF 2019]枯燥的抽奖（php_mt_seed脚本&伪随机数生成）

我们首先打开页面源码，发现一串关键代码

题解

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581- 2m-

[Zer0pts2020]Can you guess it?

点开source，发现源码

image-20240529192034651

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<?php
include 'config.php'; // FLAG is defined in config.php

if (preg_match('/config\.php\/*$/i', $_SERVER['PHP_SELF'])) {
  exit("I don't know what you are thinking, but I won't let you read it :)");
}

if (isset($_GET['source'])) {
  highlight_file(basename($_SERVER['PHP_SELF']));
  exit();
}

$secret = bin2hex(random_bytes(64));
if (isset($_POST['guess'])) {
  $guess = (string) $_POST['guess'];
  if (hash_equals($secret, $guess)) {
    $message = 'Congratulations! The flag is: ' . FLAG;
  } else {
    $message = 'Wrong.';
  }
}
?>

然后开始进行代码审计

根据题目提示，flag在config.php中，所以我们的目的是要读取config.php

题解

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492- 2m-

[FBCTF2019]RCEService

用json格式输入{“cmd”:”ls”}

image-20240529170911278

我们再查看源码（可能比赛给了源码吧，我是没找到）

题解