PatchSiren cyber security CVE debrief

CVE-2024-26920 Siemens CVE debrief

A vulnerability in the Linux kernel's tracing/trigger subsystem could allow a local attacker to cause a denial of service condition. The issue stems from improper error handling when allocating snapshot memory in the tracing trigger functionality. Specifically, when snapshot allocation fails, the code did not properly return an error code, potentially leading to undefined behavior or system instability. This affects Siemens SIMATIC S7-1500 TM MFP industrial control systems that utilize the GNU/Linux subsystem. The vulnerability requires local access and low privileges to exploit, with no user interaction needed. While no confidentiality or integrity impact occurs, successful exploitation results in high availability impact. Siemens has not released a patch for this vulnerability; mitigation relies on restricting access to trusted personnel and ensuring only applications from trusted sources are executed on affected systems.

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

Industrial control system operators using Siemens SIMATIC S7-1500 TM MFP with GNU/Linux subsystem, OT security teams, Linux kernel maintainers for embedded/ICS deployments, and organizations following CISA ICS security guidance.

Technical summary

The Linux kernel's tracing/trigger subsystem contains an error handling defect where snapshot allocation failures do not return proper error codes. Located in kernel/tracing code, this vulnerability triggers when memory allocation for tracing snapshots fails, causing the function to proceed without indicating failure to callers. The flaw requires local access with low privileges and results in high availability impact. Affected systems include Siemens SIMATIC S7-1500 TM MFP with GNU/Linux subsystem. No patch is currently available; mitigations focus on access restriction and trusted application execution.

Defensive priority

medium

Recommended defensive actions

Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
Execute only applications from trusted sources on affected systems
Monitor for anomalous local process behavior or unexpected tracing subsystem errors
Apply vendor patches when released by Siemens
Review CISA ICS recommended practices for defense-in-depth strategies

Evidence notes

CVE published 2024-04-09 per official CVE record. CISA advisory ICSA-24-102-01 published same date. Modified 2026-05-14. Source confirms affected product as SIMATIC S7-1500 TM MFP GNU/Linux subsystem. CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H confirms local attack vector with availability impact only.

Official resources

2024-04-09