A high-severity cryptographic signature verification flaw in multiple Lenze industrial controllers may allow local attackers to bypass security controls.

This vulnerability (CWE-347) involves an improper verification of cryptographic signatures within the SSH enablement process. The vulnerability requires a local attacker with low privileges to exploit, potentially leading to significant impact on confidentiality, integrity, and availability.

Successful exploitation of this flaw could allow an attacker to bypass authentication or execute unauthorized commands via the SSH mechanism. Given the CVSS score of 7.8, this represents a high-risk scenario for industrial environments, where unauthorized control over hardware could lead to operational disruption, safety hazards, or damage to proprietary physical processes.

Immediate Action: Update the affected Lenze firmware to version 1.15.2 (for c430, c520, c550), 1.14.2 (for i950 GenA), or 2.0.3 (for i950 GenB) as specified in the vendor advisory.

Proactive Monitoring: Monitor system access logs for unusual SSH authentication activity or attempts to interact with the SSH enablement service.

Compensating Controls: Restrict physical access to the affected hardware and disable SSH access if it is not required for daily operations.

Public Exploit Available: Unknown.

The vulnerability presents a high risk to the integrity of Lenze industrial hardware. Administrators should prioritize the deployment of the provided firmware updates during the next scheduled maintenance window to ensure that cryptographic protections are properly enforced.