description: Multiple Xiongmai NVR devices, including MBD6304T V4.02.R11.00000117.10001.131900.00000 and NBD6808T-PL V4.02.R11.C7431119.12001.130000.00000, allow authenticated users to execute arbitrary commands as root, as exploited in the wild starting in approximately 2019. A remote and authenticated attacker, possibly using the default admin:tlJwpbo6 credentials, can connect to port 34567 and execute arbitrary operating system commands via a crafted JSON file during an upgrade request. Since at least 2021, Xiongmai has applied patches to prevent attackers from using this mechanism to execute telnetd.