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PatchSiren cyber security CVE debrief

CVE-2021-2154 Festo Didactic SE CVE debrief

CVE-2021-2154 is a denial-of-service issue described in the supplied Festo Didactic SE MES PC advisory corpus. The affected component is the underlying Oracle MySQL Server DML path, and successful exploitation can cause a hang or a repeatedly reproducible crash of the MySQL Server process. The advisory says the attack requires high privileges and network access, so this is not a low-skill or unauthenticated issue, but it can still disrupt availability if the exposed service is reachable.

Vendor
Festo Didactic SE
Product
MES PC
CVSS
MEDIUM 4.9
CISA KEV
Not listed in stored evidence
Original CVE published
2024-02-27
Original CVE updated
2026-01-27
Advisory published
2024-02-27
Advisory updated
2026-01-27

Who should care

Operators and maintainers of Festo Didactic SE MES PC deployments, especially environments that still rely on the affected XAMPP-based stack or the underlying MySQL service. Network and platform teams should also care if administrative MySQL access is reachable across internal segments.

Technical summary

The supplied CSAF source describes CVE-2021-2154 as a MySQL Server vulnerability in the Server:DML component affecting supported versions 5.7.33 and earlier. The CVSS vector is CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H, which aligns with the advisory language: the issue is network-reachable, requires high privileges, and primarily impacts availability. In the Festo advisory context, the remediation points to replacing XAMPP on MES PCs with Factory Control Panel and obtaining the current version from Festo technical support. The source corpus also indicates the advisory was republished by CISA on 2026-01-27, but the CVE itself was published on 2024-02-27.

Defensive priority

Medium priority: apply promptly on affected MES PC systems, but the need for high privileges lowers immediate exposure compared with unauthenticated remote flaws.

Recommended defensive actions

  • Identify MES PC systems that use the affected MySQL-backed stack or any XAMPP-based deployment referenced by the advisory.
  • Obtain and deploy the current Factory Control Panel release from Festo technical support, as listed in the vendor remediation.
  • Restrict administrative and MySQL network access to only trusted management hosts and segments.
  • Review privilege assignments so MySQL administrative access is limited to the minimum set of operators and services that require it.
  • Monitor for repeated MySQL service hangs, crashes, or restart loops on affected systems.
  • Confirm backups and restoration procedures are current before maintenance, since the impact is an availability loss rather than data exposure.

Evidence notes

This debrief is based only on the supplied CSAF/CISA advisory corpus and official links. The source description states: affected versions are 5.7.33 and prior; exploitation requires high privilege and network access via multiple protocols; impact is a hang or repeatable crash of MySQL Server. The supplied CVSS vector is CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H, score 4.9 (Medium). The source metadata ties the advisory to Festo Didactic SE MES PC and lists a remediation path to Factory Control Panel. Timing context: CVE published 2024-02-27; source modified 2026-01-27.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-2154 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-2154

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

  • CVE-2021-2154 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-2154

    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-26-027-02.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://festo.csaf-tp.certvde.com/.well-known/csaf/white/2024/fsa-202402.json

    Reference

  • Source reference

    Unverified legacy reference

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

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://festo.com/psirt

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://certvde.com/en/advisories/VDE-2023-065

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-26-027-02

    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

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.