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CVE-2024-39476 Siemens CVE debrief

A deadlock vulnerability in the Linux kernel's md/raid5 subsystem could cause the raid5d() kernel thread to wait indefinitely for itself to clear the MD_SB_CHANGE_PENDING flag, resulting in a system hang. The vulnerability exists in the RAID5 driver where improper synchronization logic allows the raid5d() thread to block on a condition that only it can satisfy, creating a circular wait condition. Siemens has identified this vulnerability as affecting certain industrial networking products running SINEC OS, including the RUGGEDCOM RST2428P and SCALANCE X-family switches. The vulnerability was resolved in the Linux kernel with a fix to prevent raid5d() from waiting on itself. Organizations should apply vendor-provided firmware updates and follow defense-in-depth practices for industrial control systems.

Vendor
Siemens
Product
RUGGEDCOM RST2428P (6GK6242-6PA00)
CVSS
Unknown
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 running Siemens industrial networking equipment (SCALANCE X-family switches, RUGGEDCOM RST2428P) with SINEC OS; system administrators managing Linux systems with software RAID5 configurations; industrial control system operators relying on high-availability storage subsystems

Technical summary

The vulnerability exists in the Linux kernel's Multiple Device (md) driver, specifically in the RAID5 implementation. The raid5d() kernel thread, responsible for RAID5 array management, could enter a deadlock state by waiting for the MD_SB_CHANGE_PENDING flag to be cleared—a condition that only the raid5d() thread itself could satisfy. This creates a circular dependency where the thread blocks indefinitely, causing the RAID5 array to become unresponsive and potentially leading to system hang. The fix ensures proper synchronization to prevent raid5d() from waiting on itself.

Defensive priority

medium

Recommended defensive actions

  • Apply vendor-provided firmware updates for affected Siemens SCALANCE and RUGGEDCOM products as specified in the vendor security advisory
  • Implement network segmentation for industrial control systems to limit exposure of affected devices
  • Follow CISA recommended practices for industrial control systems defense-in-depth
  • Monitor vendor security advisories for additional affected products or updated remediation guidance
  • Review and apply Linux kernel security updates for systems utilizing md/raid5 software RAID configurations

Evidence notes

The vulnerability description indicates a resolved Linux kernel issue in md/raid5 where raid5d() could deadlock waiting for itself to clear MD_SB_CHANGE_PENDING. Siemens ProductCERT advisory SSA-613116 (republished by CISA as ICSA-25-226-15) identifies affected industrial networking products. The source advisory underwent multiple revisions, with the most recent update on 2026-02-25 correcting affected product listings and removing rejected CVEs. The threat category is marked as 'Misinformed' in the source CSAF data. No CVSS score is provided in the source material.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-39476 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-39476

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

  • CVE-2024-39476 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-39476

    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-25-226-15.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-613116.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-613116.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-226-15

    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.