CVE-2026-34021 — Lack of cryptographic protection in Wertheim SafeController 5400 enables RS-485 message sniffing and replay

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Wertheim GmbH / Wertheim SafeController 5400 Hardware for VAULT ROOMS (Safe Deposit Locker System - Microcontroller)	affected Wertheim SafeController 5400, Controller 5400 - AssemblyVersion 6.11.8130.22320

CWE

CWE-294

References

https://wertheim-safes.com/safe-deposit-boxes/
https://r.sec-consult.com/wertdev

ADP enrichment

CISA-ADP

No English description supplied.

https://sec-consult.com/vulnerability-lab/advisory/multiple-vulnerabilities-in-wertheim-safecontroller-hardware-for-vault-rooms-safe-deposit-locker-system-microcontroller/