This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of TP-Link TL-WR940N 3.20.1 Build 200316 Rel.34392n (5553) routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of file name extensions. 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 root. Was ZDI-CAN-13910.

TP-Link TL-WR940N is vulnerable to a stack-based buffer overflow, caused by improper bounds checking by the ipAddrDispose function. By sending specially crafted ICMP echo request packets, a remote authenticated attacker could overflow a buffer and execute arbitrary code on the system with elevated privileges.