Quick.Cart is vulnerable to Local File Inclusion and Path Traversal issues in the theme selection mechanism. Quick.Cart allows a privileged user to upload arbitrary file contents while only validating the filename extension. This allows an attacker to include and execute uploaded PHP code, resulting in Remote Code Execution on the server.
The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only version 6.7 was tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.