Actiontec WCB6200Q uh_get_postdata_withupload Stack-based Buffer Overflow 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. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the HTTP server. Was ZDI-CAN-21418.