The firmware on GateHouse; Harris BGAN RF-7800B-VU204 and BGAN RF-7800B-DU204; Hughes Network Systems 9201, 9450, and 9502; Inmarsat; Japan Radio JUE-250 and JUE-500; and Thuraya IP satellite terminals does not require authentication for sessions on TCP port 1827, which allows remote attackers to execute arbitrary code via unspecified protocol operations.