Unspecified vulnerability in the session extension functionality in PHP before 5.1.3 has unknown impact and attack vectors related to heap corruption.
http://www.ubuntu.com/usn/usn-320-1
http://www.securityfocus.com/bid/17843
http://www.php.net/release_5_1_3.php
http://www.mandriva.com/security/advisories?name=MDKSA-2006:122
http://securitytracker.com/id?1016306
http://secunia.com/advisories/21125