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.

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Advisories

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Fixes

Solution

No fix is available for this issue. The affected SafeController 5400 is end-of-life (EOL), and the vendor stated that no patch will be provided. Affected parties should assess the business risk and switch to a supported version if EOL products are in use.


Workaround

Physically isolate all SafeController devices so that only authorized personnel can access them. Harden all connected systems that communicate via the serial interface, disable unnecessary services, and restrict access to authorized personnel only. Ensure that servers communicating with SafeController devices use strong, unique authentication credentials and are not accessible to unauthorized users. Maintain physical security of all interconnected components to prevent unauthorized access or tampering.

History

Mon, 15 Jun 2026 14:30:00 +0000

Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 15 Jun 2026 12:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Lack of cryptographic protection in Wertheim SafeController 5400 enables RS-485 message sniffing and replay
Weaknesses CWE-294
References
Metrics cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: SEC-VLab

Published:

Updated: 2026-06-15T13:10:40.668Z

Reserved: 2026-03-25T10:46:45.515Z

Link: CVE-2026-34021

cve-icon Vulnrichment

Updated: 2026-06-15T13:10:28.635Z

cve-icon NVD

Status : Received

Published: 2026-06-15T12:16:24.230

Modified: 2026-06-15T14:16:34.060

Link: CVE-2026-34021

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-15T14:30:05Z

Weaknesses