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CVE-2024-49877 Siemens CVE debrief

CVE-2024-49877 is a NULL pointer dereference vulnerability in the Linux kernel's OCFS2 (Oracle Cluster File System 2) filesystem. The flaw occurs during cleanup operations when the OCFS2_BH_READAHEAD flag is not set, potentially causing a NULL pointer dereference in ocfs2_set_buffer_uptodate() when the buffer head (bh) is NULL. This vulnerability was originally published on August 12, 2025, and was subsequently modified on February 25, 2026. The issue affects Siemens industrial networking products running SINEC OS, specifically the RUGGEDCOM RST2428P and SCALANCE X-family switches. Notably, CISA's advisory indicates this CVE was marked as 'Misinformed' in the impact assessment, suggesting the vulnerability may not be exploitable in the affected Siemens products as initially reported, or the impact was otherwise mischaracterized. The advisory underwent multiple revisions, with the February 2026 updates correcting affected product listings and clarifying configurations. Organizations should verify their specific product configurations against Siemens' official security advisory SSA-355557 to determine actual exposure.

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

Industrial control system operators using Siemens RUGGEDCOM RST2428P or SCALANCE X-family switches; security teams managing OT/ICS environments with SINEC OS deployments; kernel maintainers and Linux distribution security teams tracking OCFS2 filesystem vulnerabilities

Technical summary

The vulnerability exists in the OCFS2 filesystem implementation within the Linux kernel. During cleanup operations, if the OCFS2_BH_READAHEAD flag is not present in the flags field, the code may proceed to call ocfs2_set_buffer_uptodate() with a NULL buffer head pointer, resulting in a NULL pointer dereference. This is a classic defensive programming issue where insufficient validation of pointer state before dereferencing leads to potential kernel panic or denial of service. The vulnerability affects Siemens industrial networking equipment running SINEC OS that incorporates the vulnerable kernel component. The 'Misinformed' classification in CISA's advisory suggests that either the vulnerability is not exploitable in the specific Siemens product context, or the initial impact assessment was incorrect.

Defensive priority

medium

Recommended defensive actions

  • Verify SINEC OS version and configuration against Siemens SSA-355557 security advisory to confirm exposure
  • Review OCFS2 filesystem usage in affected industrial control system environments
  • Apply kernel updates from Siemens ProductCERT when available for affected RUGGEDCOM and SCALANCE devices
  • Monitor CISA ICS advisories for additional guidance on ICS-CERT ICSA-25-226-07

Evidence notes

Source indicates 'Misinformed' impact classification for affected Siemens products; multiple advisory revisions corrected product scope

Sources and references

Verified primary and authoritative sources

  • CVE-2024-49877 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-49877

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

  • CVE-2024-49877 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-49877

    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.