A missing secure communication definition and an incomplete TLS validation in the upgrade service in B&R Automation Studio versions 4.0.x, 4.1.x, 4.2.x, < 4.3.11SP, < 4.4.9SP, < 4.5.5SP, < 4.6.4 and < 4.7.2 enable unauthenticated users to perform MITM attacks via the B&R upgrade server.