ZyXEL ZyWall/USG/UAG CGI Program free_time_failed.cgi err_msg cross site scripting

A vulnerability was found in ZyXEL ZyWall, USG and UAG (Firewall Software) (unknown version). It has been rated as problematic. This issue affects an unknown part of the file free_time_failed.cgi of the component CGI Program. There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.