The SIP ALG function in Realtek eCos RSDK and MSDK has a stack-based buffer overflow that allows an attacker to remotely execute code without authentication via a crafted SIP packet containing malicious SDP data. This issue can be exploited by sending a specially crafted UDP packet, and it does not require user interaction or access to the admin interface. The vulnerability is notable for allowing attacks on devices with disabled web interface access from external networks. Potentially, millions of devices, from routers to signal amplifiers, are affected.