Actiontec WCB6200Q Cookie Format String Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Actiontec WCB6200Q routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the HTTP server. A crafted Cookie header in an HTTP request can trigger the use of a format specifier from a user-supplied string. An attacker can leverage this vulnerability to execute code in the context of the HTTP server. Was ZDI-CAN-21417.