PatchSiren cyber security CVE debrief

CVE-2024-36004 Siemens CVE debrief

A vulnerability in the i40e Intel Ethernet driver affects the GNU/Linux subsystem of Siemens SIMATIC S7-1500 TM MFP industrial controllers. The issue stems from improper use of the WQ_MEM_RECLAIM flag when creating a workqueue, which can lead to memory reclaim deadlocks under memory pressure conditions. This local attack vector requires low privileges and no user interaction, with successful exploitation resulting in high availability impact (denial of service) on the affected industrial control system. The vulnerability was disclosed in April 2024 and remains unpatched as of the latest advisory update in May 2026.

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

Operators of Siemens SIMATIC S7-1500 TM MFP systems, industrial control system security teams, OT network defenders, and organizations running Intel i40e-based Ethernet in embedded Linux environments should prioritize monitoring and access restriction measures until a vendor patch is released.

Technical summary

The i40e driver in the Linux kernel incorrectly uses the WQ_MEM_RECLAIM flag when allocating its workqueue. This flag allows the kernel to reclaim memory from the workqueue under memory pressure, but in this driver's context can cause deadlocks because the workqueue may be needed for memory reclaim operations themselves. The vulnerability is local to the system, requiring authenticated access but no user interaction. Exploitation results in denial of service through system hang or crash. The affected product is the GNU/Linux subsystem of Siemens SIMATIC S7-1500 TM MFP, an industrial automation platform. No patch is currently available; mitigation relies on access controls and trusted application execution.

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 anomalous process behavior or system hangs indicative of workqueue deadlock
Apply vendor patches when Siemens releases a fix for this vulnerability
Segment affected industrial control systems from untrusted networks per ICS-CERT defense-in-depth guidance

Evidence notes

CISA ICS advisory ICSA-24-102-01 documents this vulnerability in Siemens SIMATIC S7-1500 TM MFP GNU/Linux subsystem. The advisory explicitly states 'Currently no fix is available' as of the May 2026 revision. The 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