OpenCart through 3.0.2.0 allows directory traversal in the editDownload function in admin\model\catalog\download.php via admin/index.php?route=catalog/download/edit, related to the download_id. For example, an attacker can download ../../config.php.
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.
Cross-site scripting (XSS) vulnerability in OpenCart before 2.1.0.2 allows remote attackers to inject arbitrary web script or HTML via the zone_id parameter to index.php.