Linksys Routers apply.cgi Remote Command Injection

An authenticated OS command injection vulnerability exists in various Linksys router models (tested on WRT160Nv2) running firmware version v2.0.03 via the apply.cgi endpoint. The web interface fails to properly sanitize user-supplied input passed to the ping_size parameter during diagnostic operations. An attacker with valid credentials can inject arbitrary shell commands, enabling remote code execution.