bug70219.phpt   [plain text]

--TEST--
Bug #70219 Use after free vulnerability in session deserializer
--FILE--
<?php
class obj implements Serializable {
    var $data;
    function serialize() {
        return serialize($this->data);
    }
    function unserialize($data) {
        session_start();
        session_decode($data);
    }
}

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

$data = unserialize($exploit);

for ($i = 0; $i < 5; $i++) {
    $v[$i] = 'hi'.$i;
}

var_dump($data);	
?>
--EXPECTF--
Warning: session_decode(): Failed to decode session object. Session has been destroyed in %s on line %d
array(2) {
  [0]=>
  object(obj)#%d (1) {
    ["data"]=>
    NULL
  }
  [1]=>
  array(0) {
  }
}