PatchSiren

PatchSiren cyber security CVE debrief

CVE-2018-0739 OpenSSL CVE debrief

CVE-2018-0739 is a medium-severity denial-of-service issue tied to excessive recursion in constructed ASN.1 parsing. In the supplied advisory corpus, the issue is associated with Festo Automation Suite and bundled CODESYS components, with mitigation centered on upgrading Festo Automation Suite to 2.8.0.138 or later and installing patched CODESYS releases from the official vendor source.

Vendor
OpenSSL
Product
FESTO
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2025-09-30
Original CVE updated
2025-11-13
Advisory published
2025-09-30
Advisory updated
2025-11-13

Who should care

Administrators and engineers responsible for Festo Automation Suite deployments, especially installations below 2.8.0.138 and systems using the listed CODESYS Development System versions. OT/ICS patch managers should also care because the advisory is published through CISA and addresses industrial software distribution.

Technical summary

The supplied CVE text describes a recursive ASN.1 type parsing problem that can consume stack space until the process crashes, resulting in denial of service. The advisory context maps the issue to Festo Automation Suite/CODESYS product combinations and notes that starting with Festo Automation Suite 2.8.0.138, CODESYS is no longer bundled and must be obtained and updated separately. The reported CVSS vector is AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H, indicating availability impact only.

Defensive priority

Medium

Recommended defensive actions

  • Upgrade Festo Automation Suite to version 2.8.0.138 or later.
  • Download and install the latest patched CODESYS release directly from the official CODESYS website.
  • Follow vendor installation and update guidance to ensure all security fixes are applied.
  • Keep the Festo Automation Suite connector up to date as new releases are published.
  • Monitor Festo, CODESYS, and CISA advisories for follow-on updates or clarifications.

Evidence notes

The primary source is a CISA republication of a Festo advisory (ICSA-26-076-01 / FSA-202601). The embedded CVE description text is the generic ASN.1 recursion/stack exhaustion statement that references OpenSSL fixes, while the advisory metadata identifies affected Festo Automation Suite and CODESYS versions. The vendor mapping supplied with the prompt is marked low-confidence and needs review, so the product association should be treated as advisory-supplied context rather than independently verified.

Sources and references

Verified primary and authoritative sources

  • CVE-2018-0739 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2018-0739

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

  • CVE-2018-0739 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2018-0739

    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.