CVE-2024-26960 Siemens CVE debrief

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP systems with the GNU/Linux subsystem enabled, particularly in industrial automation and control system environments where high availability is critical. System administrators responsible for securing OT/ICS environments should prioritize access controls until a patch becomes available.

Technical summary

The vulnerability is a race condition (CWE-362) in the Linux kernel's memory management swap subsystem. The specific race occurs between `free_swap_and_cache()`, which frees swap entries and associated page cache, and `swapoff()`, which deactivates swap devices. Improper synchronization between these operations could lead to use-after-free or null pointer dereference conditions, resulting in system instability or denial of service. The attack requires local access with low privileges and has low attack complexity. No confidentiality or integrity impact is associated with this vulnerability; the sole impact is to availability.

Defensive priority

medium

Recommended defensive actions

• Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
• Build and run only applications from trusted sources
• Monitor for future Siemens security advisories regarding patch availability for SSA-265688
• Apply defense-in-depth strategies for industrial control systems per CISA guidance

Evidence notes

The vulnerability description is sourced from CISA ICS Advisory ICSA-24-102-01, which references the upstream Linux kernel fix for a race condition between free_swap_and_cache() and swapoff(). 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, requiring low privileges, resulting in high availability impact. The affected product is explicitly identified as the GNU/Linux subsystem within Siemens SIMATIC S7-1500 TM MFP.

Official resources