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CVE-2025-38167 Siemens CVE debrief

CVE-2025-38167 is a Linux kernel ntfs3 null-handling flaw that Siemens and CISA map to affected SIMATIC S7-1500 CPU family products with an additional GNU/Linux subsystem. The advisory rates it CVSS 5.5 (MEDIUM) and indicates a local, low-privilege availability impact. Siemens states that no fix is currently available, so access restriction and trusted-software controls are the main defenses.

Vendor
Siemens
Product
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2025-06-10
Original CVE updated
2026-05-14
Advisory published
2025-06-10
Advisory updated
2026-05-14

Who should care

Siemens SIMATIC S7-1500 CPU operators and integrators, especially those using the affected 1518/1518F and SIPLUS variants and any deployment that exposes the additional GNU/Linux subsystem shell or application environment.

Technical summary

The underlying issue is in fs/ntfs3: hdr_first_de() returns a pointer to struct NTFS_DE that may be NULL, and the vulnerable path needs explicit NULL handling. The CISA/Siemens advisory context ties this Linux kernel issue to the SIMATIC S7-1500 CPU family products listed in the advisory. The published CVSS vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) points to local access requirements and a high availability impact, with no confidentiality or integrity impact recorded.

Defensive priority

Medium priority. Treat as a targeted availability risk for affected Siemens systems; prioritize where local shell access exists or where downtime would materially affect operations, especially because the advisory lists no fix yet.

Recommended defensive actions

  • Limit access to the interactive shell of the additional GNU/Linux subsystem to trusted personnel only.
  • Only build and run applications from trusted sources.
  • Monitor Siemens ProductCERT advisory SSA-082556 and CISA advisory ICSA-25-162-05 for any future remediation updates.
  • Review local user access and privilege boundaries for the affected subsystem to reduce exposure to low-privilege local abuse.

Evidence notes

The source advisory (ICSA-25-162-05 / Siemens SSA-082556) lists five affected Siemens SIMATIC S7-1500 CPU product variants and explicitly states that currently no fix is available. The CVE description identifies the Linux kernel ntfs3 issue: hdr_first_de() can return NULL and needs error handling, which is consistent with CWE-476 (NULL pointer dereference) and the advisory's CVSS vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. The advisory also notes the finding came from the Linux Verification Center (linuxtesting.org) with SVACE.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-38167 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-38167

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

  • CVE-2025-38167 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-38167

    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-25-162-05.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-082556.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-082556.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-162-05

    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.