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CVE-2024-43894 Siemens CVE debrief

A null pointer dereference vulnerability exists in the Linux kernel's Direct Rendering Manager (DRM) client subsystem. Specifically, in the `drm_client_modeset_probe()` function, a failure of `drm_mode_duplicate()` can return NULL, which was not properly checked before subsequent dereference. The vulnerability was remediated by adding an explicit NULL check. The issue affects Siemens industrial networking products running SINEC OS, which incorporate the vulnerable Linux kernel component. CISA published advisory ICSA-25-226-07 on August 12, 2025, with subsequent revisions through February 25, 2026, to clarify affected product configurations and remove rejected CVE entries. Siemens ProductCERT issued security advisory SSA-355557 to address third-party component vulnerabilities in their SINEC OS platform. The vulnerability is classified with impact category 'Misinformed' in the CSAF source data. No CVSS score is available in the provided source corpus.

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 operating Siemens industrial networking infrastructure, particularly those deploying RUGGEDCOM RST2428P switches or SCALANCE X-family managed switches with SINEC OS. OT security teams, ICS asset owners, and critical infrastructure operators should prioritize vendor patch availability and implement defense-in-depth controls per CISA guidance.

Technical summary

The vulnerability exists in the Linux kernel's DRM (Direct Rendering Manager) client implementation. The function `drm_client_modeset_probe()` calls `drm_mode_duplicate()`, which can fail and return NULL. The original code did not validate this return value before dereferencing, leading to a null pointer dereference condition. The remediation adds an explicit NULL check after the `drm_mode_duplicate()` call. This is a classic missing validation vulnerability (CWE-20: Improper Input Validation) in kernel-mode code. The vulnerability affects Siemens industrial networking products (RUGGEDCOM RST2428P, SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, SCALANCE XCM-/XRM-/XCH-/XRH-300 family) that incorporate the vulnerable Linux kernel through SINEC OS. The CSAF source categorizes the threat impact as 'Misinformed', suggesting potential information disclosure or integrity concerns rather than direct code execution.

Defensive priority

medium

Recommended defensive actions

  • Review Siemens ProductCERT advisory SSA-355557 for detailed product-specific guidance and patch availability
  • Apply vendor-provided firmware updates for affected SINEC OS-based products when available
  • Implement network segmentation for industrial control systems per CISA ICS recommended practices
  • Monitor CISA ICS advisories for updates to ICSA-25-226-07

Evidence notes

Source corpus indicates this vulnerability originates from the Linux kernel DRM subsystem (drm/client), specifically a null pointer dereference in drm_client_modeset_probe() when drm_mode_duplicate() fails. The fix involved adding a NULL check. Siemens ProductCERT SSA-355557 and CISA ICSA-25-226-07 document this as affecting third-party components in SINEC OS. The CSAF source marks impact as 'Misinformed' for products CSAFPID-0006, CSAFPID-0002, and CSAFPID-0003. Revision history shows advisory updates on 2026-02-12 (corrected affected products), 2026-02-24 (clarified SCALANCE family configurations, removed rejected CVEs), and 2026-02-25 (CISA republication based on Siemens advisory).

Sources and references

Verified primary and authoritative sources

  • CVE-2024-43894 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-43894

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

  • CVE-2024-43894 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-43894

    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.