A stack overflow vulnerability in the WebCam Server Login functionality of GeoVision GV-VMS V20.0.2 allows an unauthenticated attacker to send a specially crafted HTTP request that can trigger arbitrary code execution. The flaw arises from an unchecked use of sscanf that copies attacker-controlled input into fixed-size buffers without size limitation, leading to overflow. Successful exploitation could result in SYSTEM-level code execution on the affected machine.