PLANET GS-4210-16P2S V3 Stack Buffer Overflow and NULL Pointer Dereference via dispatcher.cgi RADIUS Handlers

PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the radKey, radKey_0, radDftParamKey, radName, and radIp POST parameters into fixed-size stack buffers without length validation, and additionally dereferences radName and radIp without verifying their presence in the request. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.