CVE-2019-9011 Festo CVE debrief

Who should care

OT/ICS administrators, engineers, and security teams responsible for CODESYS-based tooling, Festo Automation Suite deployments, and any exposed authentication interface that could be probed for valid account names.

Technical summary

The issue is username enumeration: an attacker can distinguish valid from invalid usernames through the affected product's authentication behavior. The supplied CVSS vector (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) matches a remote, unauthenticated disclosure with limited confidentiality impact and no direct integrity or availability impact.

Defensive priority

Medium. Prioritize if the affected software is reachable from untrusted networks or used in environments where account names can be leveraged for follow-on phishing or password attacks; otherwise address it in the next maintenance window.

Recommended defensive actions

• Verify the exact affected product and version against the vendor advisory before making changes, because the supplied corpus is inconsistent about whether the issue applies to Pilz PMC programming tool or Festo/CODESYS-b
• Update to the latest patched CODESYS release referenced by the vendor guidance, and apply the corresponding Festo Automation Suite update; the corpus states that Festo Automation Suite 2.8.0.138 no longer bundles CODESYS
• Follow the installation and update instructions provided by CODESYS so that all security fixes are applied, and keep monitoring CODESYS security advisories for new fixes
• Use CISA industrial control system recommended practices to reduce exposure of authentication services and to limit access to affected management interfaces

Evidence notes

The source corpus contains a product-mapping inconsistency: the CVE description says 'Pilz PMC programming tool 3.x before 3.5.17 (based on CODESYS Development System),' while the CISA CSAF source item republishes a Festo advisory for Festo Automation Suite and bundled CODESYS components. The defensive summary is therefore limited to the evidence provided and avoids assuming a single definitive product owner beyond the supplied sources.

Sources and references

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.