bug70436.phpt   [plain text]

--TEST--
Bug #70436: Use After Free Vulnerability in unserialize()
--FILE--
<?php

class obj implements Serializable
{
	var $data;
	
	function serialize()
	{
		return serialize($this->data);
	}
	
	function unserialize($data)
	{
		$this->data = unserialize($data);
	}
}

$fakezval = ptr2str(1122334455);
$fakezval .= ptr2str(0);
$fakezval .= "\x00\x00\x00\x00";
$fakezval .= "\x01";
$fakezval .= "\x00";
$fakezval .= "\x00\x00";

$inner = 'C:3:"obj":3:{ryat';
$exploit = 'a:4:{i:0;i:1;i:1;C:3:"obj":'.strlen($inner).':{'.$inner.'}i:2;s:'.strlen($fakezval).':"'.$fakezval.'";i:3;R:5;}';

$data = unserialize($exploit);

var_dump($data);

function ptr2str($ptr)
{
	$out = '';
	
	for ($i = 0; $i < 8; $i++) {
		$out .= chr($ptr & 0xff);
		$ptr >>= 8;
	}
	
	return $out;
}
?>
DONE
--EXPECTF--
Notice: unserialize(): Error at offset 0 of 3 bytes in %sbug70436.php on line %d

Notice: unserialize(): Error at offset 17 of 17 bytes in %sbug70436.php on line %d
array(4) {
  [0]=>
  int(1)
  [1]=>
  object(obj)#%d (1) {
    ["data"]=>
    bool(false)
  }
  [2]=>
  string(24) "%s"
  [3]=>
  bool(false)
}
DONE