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PatchSiren cyber security CVE debrief

CVE-2023-37546 CODESYS CVE debrief

CVE-2023-37546 affects multiple CODESYS products and Festo Automation Suite deployments that bundle specific CODESYS versions. After successful user authentication, crafted network communication requests with inconsistent content can make the CmpApp component read from an invalid internal address, which can lead to a denial-of-service condition. The issue is documented in CISA’s republication of the Festo advisory and is distinct from CVE-2023-37545, CVE-2023-37547, CVE-2023-37548, CVE-2023-37549, and CVE-2023-37550.

Vendor
CODESYS
Product
FESTO
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2025-04-10
Original CVE updated
2025-04-10
Advisory published
2025-04-10
Advisory updated
2025-04-10

Who should care

OT/ICS operators using Festo Automation Suite, administrators of CODESYS-based engineering or runtime environments, and vulnerability management teams responsible for availability-sensitive industrial systems.

Technical summary

The advisory describes an authenticated network-triggered availability issue in the CmpApp component. An attacker must first authenticate as a user, then send specific crafted requests with inconsistent content to provoke an internal read from an invalid address. The reported impact is denial of service only (CVSS 6.5, AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Affected configurations listed in the source include Festo Automation Suite versions below 2.8.0.138 with bundled CODESYS Development System 3.0 or 3.5.16.10, and CODESYS Development System 3.5.21.20 as an external component of Festo Automation Suite 2.8.0.138.

Defensive priority

Medium. Prioritize if the affected CODESYS/Festo stack is present in production or safety-relevant environments, since availability loss in OT systems can have outsized operational impact.

Recommended defensive actions

  • Inventory Festo Automation Suite and CODESYS installations and match them against the affected version combinations listed in the advisory.
  • Upgrade to the latest patched CODESYS release from the official CODESYS website and follow the vendor’s installation/update guidance.
  • If using Festo Automation Suite, update to version 2.8.0.138 or later and verify the required CODESYS component has been updated separately, since CODESYS is no longer bundled starting with that release.
  • Keep the Festo Automation Suite connector updated by applying Festo releases as they are issued.
  • Restrict authenticated access to engineering and maintenance accounts using least privilege and strong access controls.
  • Monitor for anomalous authenticated requests affecting CODESYS/CmpApp-related traffic and prepare maintenance and recovery plans to restore availability if needed.

Evidence notes

The source corpus is CISA’s CSAF republication of the Festo advisory for “CODESYS in Festo Automation Suite,” published 2026-02-26 and revised 2026-03-17. The advisory lists affected Festo Automation Suite/CODESYS version combinations and recommends updating to patched CODESYS and keeping Festo Automation Suite components current. The supplied data marks the issue as not present in CISA KEV. Vendor metadata in the prompt is inconsistent, so product applicability should be validated against the installed Festo/CODESYS combination rather than the vendor label alone.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-37546 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-37546

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

  • CVE-2023-37546 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-37546

    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-26-076-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://festo.csaf-tp.certvde.com/.well-known/csaf/white/2026/fsa-202601.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://certvde.com/en/advisories/vendor/festo/

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.festo.com/psirt

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://certvde.com/en/advisories/VDE-2025-108

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cve.org/CVERecord?id=CVE-2025-2595

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-26-076-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01

    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.