The Wertheim SafeController 5400, Controller 5400 - AssemblyVersion 6.11.8130.22320, uses RS-485 communication between the server and the microcontroller without cryptographic protection. An attacker with access to the communication path between the server and the microcontroller can sniff RS-485 messages and replay previously observed messages. This can be used, for example, to spoof a "quit alarm" message and continuously deactivate the safe alarm.
Credits
Gorazd Jank, SEC Consult Vulnerability Lab
Christian Hager, SEC Consult Vulnerability Lab
Philipp Espernberger, SEC Consult Vulnerability Lab
