In createInstanceFromNamedArguments in Shopware through 5.6.x, a crafted web request can trigger a PHP object instantiation vulnerability, which can result in an arbitrary deserialization if the right class is instantiated. An attacker can leverage this deserialization to achieve remote code execution. NOTE: this issue is a bypass for a CVE-2017-18357 whitelist patch.
Shopware before 5.3.4 has a PHP Object Instantiation issue via the sort parameter to the loadPreviewAction() method of the Shopware_Controllers_Backend_ProductStream controller, with resultant XXE via instantiation of a SimpleXMLElement object.