CVE-2024-26906 Siemens CVE debrief

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP programmable logic controllers with the GNU/Linux subsystem enabled, particularly in industrial automation, manufacturing, and critical infrastructure environments. Security teams responsible for OT/ICS asset protection, system integrators deploying these controllers, and compliance officers managing industrial cybersecurity frameworks should prioritize assessment and mitigation.

Technical summary

The vulnerability resides in the Linux kernel's x86 architecture-specific memory management code. The `copy_from_kernel_nofault()` function, designed to safely copy data from kernel space with fault handling, incorrectly allowed read operations targeting the vsyscall page. The vsyscall page is a legacy mechanism that maps certain kernel system calls into user space for performance optimization on x86_64 systems. Improper access to this page can trigger kernel faults or instability. A local attacker with low privileges can exploit this flaw to cause a denial of service condition. The vulnerability has been assigned CVSS 3.1 score 5.5 (Medium) with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating local attack vector, low complexity, low privilege requirements, and high availability impact with no confidentiality or integrity impact.

Defensive priority

medium

Recommended defensive actions

• Restrict interactive shell access to the GNU/Linux subsystem on affected Siemens SIMATIC S7-1500 TM MFP devices to trusted personnel only
• Implement application whitelisting to ensure only trusted, verified applications are built and executed on the GNU/Linux subsystem
• Monitor for anomalous local process activity that may indicate exploitation attempts against kernel memory access functions
• Apply defense-in-depth strategies including network segmentation for industrial control systems per CISA ICS recommended practices
• Subscribe to Siemens ProductCERT security advisories for notification when a security patch becomes available

Evidence notes

The vulnerability was disclosed in CISA ICS Advisory ICSA-24-102-01 on April 9, 2024, with subsequent advisory updates through September 2025 adding related CVEs to the same product security notice. Siemens has confirmed no fix is available as of the latest advisory revision. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) indicates local attack vector with low attack complexity and low privileges required, resulting in high availability impact.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.