PatchSiren cyber security CVE debrief

CVE-2024-45018 Siemens CVE debrief

A missing initialization vulnerability in the Linux kernel's netfilter flowtable subsystem affects Siemens SIMATIC S7-1500 TM MFP industrial control systems. The flaw involves an uninitialized extack (extended ACK) structure in flow offload operations, which can lead to undefined behavior. With a CVSS 3.1 score of 5.5 (MEDIUM), this local vulnerability requires low privileges but no user interaction, potentially causing high availability impact. The vulnerability was disclosed in April 2024 and affects the GNU/Linux subsystem of this industrial PLC product. Siemens has not released a patch; mitigation relies on access restrictions and trusted application practices.

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, OT security teams, and organizations deploying Siemens SIMATIC S7-1500 TM MFP programmable logic controllers in manufacturing, process control, or critical infrastructure environments

Technical summary

The vulnerability exists in the Linux kernel's netfilter flowtable subsystem where the extack (extended ACK) structure is not properly initialized before use in flow offload operations. This missing initialization (CWE-456) in kernel networking code can result in undefined behavior with potential availability impact. The flaw is local to the system, requiring low privileges but no user interaction. Affected systems use the GNU/Linux subsystem within Siemens SIMATIC S7-1500 TM MFP industrial PLCs. No patch is currently available from the vendor.

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
Apply defense-in-depth practices for industrial control system environments

Evidence notes

The vulnerability description indicates missing initialization of extack in netfilter flowtable flow offload operations. CVSS vector confirms local attack vector with low attack complexity and high availability impact. Siemens CSAF advisory ICSA-24-102-01 (updated through September 2025) documents affected product and remediation status. No fix available per vendor remediation statement.

Official resources

2024-04-09