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PatchSiren cyber security CVE debrief

CVE-2023-23455 Siemens CVE debrief

CVE-2023-23455 is a Linux kernel type-confusion vulnerability in atm_tc_enqueue that can result in denial of service. Siemens’ CSAF advisory ICSA-25-044-09 maps the issue to multiple SCALANCE WAB/WAM/WUB/WUM products and directs customers to update to V3.0.0 or later.

Vendor
Siemens
Product
SCALANCE WAB762-1 (6GK5762-1AJ00-6AA0)
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2023-06-13
Original CVE updated
2024-04-09
Advisory published
2023-06-13
Advisory updated
2024-04-09

Who should care

OT/ICS defenders and Siemens SCALANCE operators should care, especially teams responsible for the listed WAB/WAM/WUB/WUM product lines and any environment running firmware/software versions earlier than the vendor-fixed release.

Technical summary

The flaw is described as a type confusion in net/sched/sch_atm.c: non-negative values can sometimes represent TC_ACT_SHOT rather than a valid classification result. The supplied CVSS vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) indicates a local, low-privilege path with primary impact to availability. Siemens’ advisory applies the CVE to 19 SCALANCE product identifiers and states the fix is V3.0.0 or later.

Defensive priority

Medium. The score is moderate, the path is local, and there is no KEV entry in the supplied timeline, but the availability impact can matter in industrial environments.

Recommended defensive actions

  • Upgrade affected Siemens SCALANCE products to V3.0.0 or later, per the vendor remediation.
  • Inventory SCALANCE WAB/WAM/WUB/WUM devices to confirm whether any listed product IDs are deployed.
  • Validate current firmware/software versions against the Siemens advisory before scheduling maintenance.
  • Apply least-privilege and restrict local administrative access on affected systems.
  • Follow CISA ICS defense-in-depth and recommended-practices guidance for segmentation, hardening, backup, and recovery planning.

Evidence notes

Primary evidence comes from the CISA CSAF source item ICSA-25-044-09 and Siemens ProductCERT references. The advisory states the CVE affects multiple Siemens SCALANCE products and that remediation is to update to V3.0.0 or later. The source revision history supplied here shows a 2025-05-06 revision for typo fixes only, not a new vulnerability date.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-23455 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-23455

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

  • CVE-2023-23455 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-23455

    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-25-044-09.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-769027.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-769027.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-044-09

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/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://us-cert.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.