CVE-2024-6119 Siemens CVE debrief

Who should care

OT operators, network and security teams, and application owners using the affected Siemens SCALANCE wireless products in deployments that validate peer certificates by expected name. This is most relevant where the device or adjacent software performs TLS client-side certificate name checking.

Technical summary

The advisory describes a memory-safety fault in certificate name comparison logic. Basic certificate chain validation is not affected, but if an application also checks an expected DNS name, email address, or IP address, an X.509 certificate containing an `otherName` SAN may cause an invalid memory access and abnormal termination. Siemens notes that this is generally a client-side name-checking issue; TLS servers are usually not impacted because they typically do not perform reference-identifier name checks in the same way.

Defensive priority

High for environments running affected SCALANCE variants that rely on certificate name validation, because a malformed certificate can crash the application and disrupt service. Prioritize exposed OT deployments and any systems that terminate or proxy TLS for industrial workflows.

Recommended defensive actions

• Upgrade affected Siemens SCALANCE products to V3.0.0 or later, per the Siemens remediation guidance.
• Inventory where these products are deployed and determine whether any TLS workflows perform certificate name checks against DNS name, email address, or IP address identifiers.
• Test remediation in a maintenance window and verify that dependent OT communications still function after the update.
• Monitor for application crashes or unexpected terminations in TLS-enabled components that validate peer certificates.
• Use the Siemens and CISA advisories to confirm the exact affected model and firmware mapping before scheduling changes.

Evidence notes

Source evidence comes from the CISA CSAF advisory ICSA-25-044-09 and the linked Siemens advisory SSA-769027. The supplied advisory content states that 19 Siemens SCALANCE product variants are affected and that V3.0.0 or later is the vendor fix. The advisory publication date is 2025-02-11 and the later 2025-05-06 update is listed as typo fixes only. The advisory narrative emphasizes abnormal termination / denial of service in applications performing certificate name checks; it also states that basic chain validation is not affected and that TLS servers are generally not affected.

Official resources