A vulnerability has been discovered in Moxa MGate which allows an attacker to perform a man-in-the-middle (MITM) attack on the device. This affects MGate MB3170 Series Firmware Version 4.2 or lower. and MGate MB3270 Series Firmware Version 4.2 or lower. and MGate MB3280 Series Firmware Version 4.1 or lower. and MGate MB3480 Series Firmware Version 3.2 or lower.