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CVE-2024-39503 Siemens CVE debrief

A use-after-free vulnerability exists in the Linux kernel's netfilter ipset subsystem, specifically within the list:set type. The race condition occurs between namespace cleanup operations and garbage collection (gc) during RCU cleanup. When namespace cleanup destroys list:set type sets while garbage collection is waiting to run, the gc process subsequently accesses data from the already-destroyed set, resulting in use-after-free memory corruption. This vulnerability affects Siemens industrial networking products that incorporate the vulnerable Linux kernel components. The issue was initially published on August 12, 2025, with subsequent advisory updates through February 25, 2026, including corrections to affected product listings and clarifications regarding specific product family configurations.

Vendor
Siemens
Product
RUGGEDCOM RST2428P (6GK6242-6PA00)
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2025-08-12
Original CVE updated
2026-02-25
Advisory published
2025-08-12
Advisory updated
2026-02-25

Who should care

Organizations operating Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, SCALANCE XCM-/XRM-/XCH-/XRH-300 family, or RUGGEDCOM RST2428P industrial networking equipment. System administrators responsible for Linux-based industrial control systems using netfilter ipset with list:set configurations. Security teams monitoring OT/ICS environments for kernel-level vulnerabilities.

Technical summary

The vulnerability exists in the Linux kernel's netfilter ipset implementation, specifically the list:set type. A race condition between namespace cleanup and garbage collection (gc) operations during RCU cleanup can cause the gc process to access freed memory. When namespace cleanup destroys list:set type sets, the pending gc operation may still reference data from the destroyed set, resulting in use-after-free. This is a memory safety issue in kernel networking code that could potentially lead to denial of service or other undefined behavior. The vulnerability affects Siemens industrial networking products that incorporate vulnerable Linux kernel versions.

Defensive priority

medium

Recommended defensive actions

  • Apply vendor-provided firmware updates for affected Siemens SCALANCE and RUGGEDCOM products when available
  • Monitor Siemens ProductCERT advisory SSA-355557 for updated patch availability
  • Implement network segmentation to limit exposure of affected industrial control system devices
  • Follow CISA ICS recommended practices for defense-in-depth strategies
  • Review and apply Linux kernel security updates for systems under organizational control that use netfilter ipset with list:set configurations

Evidence notes

Vulnerability description sourced from CISA CSAF advisory ICSA-25-226-07 and Siemens ProductCERT SSA-355557. The use-after-free condition is specifically tied to the list:set type implementation in netfilter ipset. Advisory revision history indicates initial publication on 2025-08-12, with multiple updates through 2026-02-25 correcting product impact assessments.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-39503 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-39503

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2024-39503 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-39503

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-226-07.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-355557.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-355557.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-226-07

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.