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CVE-2024-39495 Siemens CVE debrief

A use-after-free vulnerability exists in the Linux kernel greybus subsystem, specifically in the gb_interface_release function, due to a race condition. The vulnerability was published on 2025-08-12 and last modified on 2026-02-25. Siemens ProductCERT issued advisory SSA-355557 addressing third-party components in SINEC OS, which CISA subsequently republished as ICSA-25-226-07. The advisory was revised multiple times, with the most recent update on 2026-02-25 clarifying affected configurations for the SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family and removing several rejected CVEs from earlier versions. The vulnerability affects Siemens industrial networking products running SINEC OS that incorporate the vulnerable greybus kernel module. The CVSS v3.1 score of 5.5 (MEDIUM) indicates moderate severity with local attack vector requirements. The use-after-free condition in gb_interface_release could potentially lead to memory corruption, though the specific impact depends on the race condition window and subsequent memory access patterns.

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 industrial networking infrastructure with SINEC OS, particularly those deploying RUGGEDCOM RST2428P or SCALANCE XC/XR/XCM/XRM/XCH/XRH series switches. OT security teams responsible for patch management in manufacturing, energy, transportation, and critical infrastructure sectors using Siemens networking equipment.

Technical summary

The vulnerability exists in the greybus kernel subsystem's gb_interface_release function, where a race condition can lead to use-after-free memory access. Greybus (Grey Bus) is a subsystem originally developed for Google's Project Ara modular smartphone, now present in the mainline Linux kernel. The race condition occurs during interface release operations, potentially allowing memory corruption if an attacker can trigger the specific timing window. The vulnerability requires local access to exploit, consistent with the MEDIUM CVSS severity rating. Siemens industrial networking products incorporating this kernel module in SINEC OS are affected, including RUGGEDCOM RST2428P and SCALANCE X-family switches under specific configurations.

Defensive priority

medium

Recommended defensive actions

  • Review Siemens ProductCERT advisory SSA-355557 for detailed product-specific guidance and patch availability
  • Verify SINEC OS version and greybus module status on affected Siemens industrial networking equipment
  • Apply vendor-provided firmware updates when available per Siemens ProductCERT recommendations
  • Implement network segmentation for industrial control systems to limit potential attack surface
  • Follow CISA ICS recommended practices for defense-in-depth strategies
  • Monitor CISA ICS advisories for updates to ICSA-25-226-07

Evidence notes

Primary source is CISA CSAF advisory ICSA-25-226-07, republished from Siemens ProductCERT SSA-355557. Advisory revision history shows four updates: initial publication (2025-08-12), corrected product lists (2026-02-12), clarified affected configurations and removed rejected CVEs (2026-02-24), and final CISA republication update (2026-02-25). The threat category in source data is marked as 'Misinformed' for affected products CSAFPID-0006, CSAFPID-0002, and CSAFPID-0003.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-39495 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-39495

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

  • CVE-2024-39495 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-39495

    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.