CVE-2014-3990
The Cart::getProducts method in system/library/cart.php in OpenCart 1.5.6.4 and earlier allows remote attackers to conduct server-side request forgery (SSRF) attacks or possibly conduct XML External Entity (XXE) attacks and execute arbitrary code via a crafted serialized PHP object, related to the quantity parameter in an update request.
Source: CVE-2014-3990