[Level 02] Lord of SQL injection – cobolt

Lord of SQL injection – cobolt

Level 02

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Source Code

<?php
  include "../config.php"; 
  login_chk();
  dbconnect();
  if(preg_match('/prob|_|\.|\(\)/i', $_GET[id])) exit("No Hack ~_~"); 
  if(preg_match('/prob|_|\.|\(\)/i', $_GET[pw])) exit("No Hack ~_~"); 
  $query = "select id from prob_cobolt where id='{$_GET[id]}' and pw=md5('{$_GET[pw]}')"; 
  echo "<hr>query : <strong>{$query}</strong><hr><br>"; 
  $result = @mysql_fetch_array(mysql_query($query)); 
  if($result['id'] == 'admin') solve("cobolt");
  elseif($result['id']) echo "<h2>Hello {$result['id']}<br>You are not admin :(</h2>"; 
  highlight_file(__FILE__); 
?>

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Analyse

http://los.sandbox.cash/cobolt-~~.php?id=abc&pw=123 이라고 입력하게 되면
select id from prob_cobolt where id='abc' and pw=md5('123') 와 같이 MySQL 쿼리문이 입력된다. 
하지만 gremlin 문제와는 달리 pw가 md5로 해쉬화 되고 있고  10번째 줄을 보면
&result['id']에 반드시 admin이 들어가야 cobolt 문제가 풀린다.

Frist Hint is next page