PatchSiren cyber security CVE debrief

CVE-2024-26895 Siemens CVE debrief

CVE-2024-26895 is a use-after-free vulnerability in the Linux kernel's wilc1000 Wi-Fi driver, affecting the cleanup of virtual interfaces (vif). The flaw occurs when all interfaces are being cleaned up, potentially leading to memory corruption. Siemens has identified this vulnerability as affecting the GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP industrial control system. The vulnerability was published on April 9, 2024, and the advisory has been updated multiple times through September 2025 to include additional related CVEs. With a CVSS 3.1 score of 5.5 (MEDIUM), the vulnerability requires local access and low privileges to exploit, with a high impact on availability. No patch is currently available from Siemens.

Vendor: Siemens
Product: SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS: MEDIUM 5.5
CISA KEV: Not listed in stored evidence
Original CVE published: 2024-04-09
Original CVE updated: 2026-05-14
Advisory published: 2024-04-09
Advisory updated: 2026-05-14

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP systems in industrial environments, particularly those utilizing the GNU/Linux subsystem for custom applications. System integrators and OT security teams responsible for maintaining availability of industrial control systems should prioritize access controls until a patch becomes available.

Technical summary

The vulnerability exists in the wilc1000 Wi-Fi driver within the Linux kernel, specifically during the cleanup of all virtual interfaces (vif). A use-after-free condition can occur when the vif structure is accessed after being freed during interface teardown. This affects the GNU/Linux subsystem of Siemens SIMATIC S7-1500 TM MFP, an industrial programmable logic controller with embedded Linux capabilities. The vulnerability requires local access and low privileges to trigger, with exploitation resulting in denial of service (high availability impact). No confidentiality or integrity impacts are associated with this vulnerability per the CVSS vector.

Defensive priority

medium

Recommended defensive actions

Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
Build and run applications only from trusted sources
Monitor for future security updates from Siemens for patch availability
Apply defense-in-depth strategies for industrial control systems per CISA guidance
Review network segmentation to limit exposure of affected systems

Evidence notes

Vulnerability description and affected product information sourced from CISA CSAF advisory ICSA-24-102-01. CVSS vector confirms local attack vector with availability impact. Siemens advisory SSA-265688 provides product-specific context. The advisory revision history shows ongoing updates through September 2025, with the most recent update on September 9, 2025 (Additional Release 9) adding 51 CVEs.

Official resources

2024-04-09