Synway SMG Gateway Management Software contains an OS command injection vulnerability in the RADIUS configuration endpoint at /en/9-2radius.php where the radius_address POST parameter is split and interpolated directly into a sed command without sanitization. An unauthenticated remote attacker can inject arbitrary shell commands by submitting a POST request with crafted radius_address, radius_address2, shared_secret2, source_ip, timeout, or retry parameters along with save=1 and enable_radius=1 to achieve remote code execution. Exploitation evidence was first observed by the Shadowserver Foundation on 2025-07-11 (UTC).