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CVE-2024-47704 Siemens CVE debrief

CVE-2024-47704 is a medium-severity availability issue in the Linux kernel's drm/amd/display path. The source advisory says dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc, so a null-pointer check is needed before dereference. The published CVSS is 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), which fits a local, availability-only defect. The advisory data also maps the issue to Siemens SIMATIC CN 4100 versions before 5.0, but that product mapping is low-confidence because the vulnerability description itself is kernel-focused; confirm exposure against the vendor advisory before prioritizing remediation.

Vendor
Siemens
Product
SIMATIC CN 4100
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-12
Original CVE updated
2026-05-14
Advisory published
2026-05-12
Advisory updated
2026-05-14

Who should care

Asset owners and operators who believe they have Siemens SIMATIC CN 4100 devices running versions before 5.0, plus Linux kernel and embedded-platform maintainers who track the referenced drm/amd/display fix in downstream builds.

Technical summary

The advisory describes a null-pointer dereference risk in Linux kernel display-driver code. In certain paths, dp_enable_link_phy and dp_disable_link_phy can receive link_res without hpo_dp_link_enc initialized, so dereferencing link_res->hpo_dp_link_enc without a null check can trigger a crash. The source cites this as two Coverity FORWARD_NULL findings and assigns CVE-2024-47704 with CVSS 5.5. The remediation field recommends updating to V5.0 or later for the Siemens product entry associated with the advisory.

Defensive priority

Medium overall; higher if you have confirmed exposure in a production industrial environment because the impact is availability loss rather than code execution, and service disruption can still be operationally significant.

Recommended defensive actions

  • Verify whether any deployed assets actually match the Siemens advisory product/version scope before treating them as affected.
  • If affected, update to V5.0 or later as recommended in the advisory.
  • Review downstream Linux kernel or vendor BSP builds to ensure the null check for hpo_dp_link_enc is present.
  • Monitor the Siemens and CISA advisory pages for any revision history or clarification.
  • Plan for availability impact by ensuring failover, recovery, and maintenance windows are documented for the affected systems.

Evidence notes

The source CSAF advisory states: 'Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing.' It also records the product as 'Siemens SIMATIC CN 4100 vers:intdot/<5.0' and lists remediation 'Update to V5.0 or later version.' However, the core description is a Linux kernel drm/amd/display issue, so the vendor/product association should be treated as needing review. Published and modified dates used here come from the supplied CVE/source timeline: published 2026-05-12 and modified 2026-05-14.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-47704 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-47704

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

  • CVE-2024-47704 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-47704

    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/2026/icsa-26-134-10.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-032379.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-032379.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-26-134-10

    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.