source: https://www.securityfocus.com/bid/13406/info

PHPCart is prone to a remote input validation vulnerability. The issue exists because the software fails to sufficiently sanitize URI parameter data that is employed when computing product charges.

A remote attacker may exploit this issue to manipulate invoice and payment charges for a specific PHPCart order.

http://www.example.com/phpcart.php?action=add&id=1002&descr=Mobile%20Phone&price=0&postage=&quantity=100