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PatchSiren cyber security CVE debrief

CVE-2024-58240 Siemens CVE debrief

The supplied advisory for CVE-2024-58240 describes a Linux kernel TLS change that separates no-async decryption handling from async handling, with a stated goal of simplifying completion handling and reducing future fix complexity. The source assigns CVSS 3.1 7.3 (HIGH) and recommends updating to V5.0 or later where applicable. However, the supplied metadata maps the issue to Siemens SIMATIC CN 4100 with low confidence, so teams should verify whether their specific product or firmware line is actually affected before treating it as actionable.

Vendor
Siemens
Product
SIMATIC CN 4100
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2025-08-28
Original CVE updated
2026-08-19
Advisory published
2025-08-28
Advisory updated
2026-08-19

Who should care

Operators and maintainers of Siemens SIMATIC CN 4100 environments, Linux kernel-based appliance owners, and OT/IT security teams responsible for validating vendor advisory applicability and scheduling firmware or software updates.

Technical summary

According to the source description, the kernel fix splits TLS decryption request handling so the non-async path no longer uses the same reference-counting flow as the async path. The advisory notes that the issue is not currently being described as a use-after-free in this report, and references an earlier race fix (aec7961916f3) as part of the historical context. The provided CVSS vector is AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L, indicating network-reachable exposure with low confidentiality, integrity, and availability impact per the source.

Defensive priority

High priority for potentially affected deployments because the source rates the issue HIGH and provides a vendor fix, but confirm product applicability first due to the Linux-kernel-versus-Siemens mapping inconsistency in the supplied data.

Recommended defensive actions

  • Verify whether your Siemens SIMATIC CN 4100 deployment matches the affected product/version scope in the advisory.
  • If applicable, update to V5.0 or later as recommended in the supplied remediation.
  • Review the Siemens CSAF and CISA advisory references to confirm the exact affected components and deployment conditions.
  • Track the CVE record and vendor advisory for any follow-up clarifications or revised applicability guidance.
  • Prioritize patching in maintenance windows for internet-reachable or operationally sensitive systems if the advisory is confirmed to apply.

Evidence notes

Timing and scope are taken from the supplied source corpus: published 2026-05-12 and modified/republished 2026-05-14. The advisory metadata includes a CVSS 3.1 vector of AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L and a remediation to update to V5.0 or later. The source also flags the vendor/product mapping as low confidence and needs review, while the narrative description itself refers to Linux kernel TLS decryption handling. This makes applicability validation especially important before operational action.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-58240 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-58240

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

  • CVE-2024-58240 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-58240

    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.