CVE-2006-20001 Festo Didactic SE CVE debrief

Who should care

Operators and maintainers of Festo Didactic SE MES PC systems, OT/ICS administrators, and teams responsible for any bundled Apache HTTP Server/XAMPP component that may still be in use on those systems.

Technical summary

According to the advisory text, a carefully crafted If: request header can cause a memory read, or write a single zero byte, in pool (heap) memory beyond the supplied header value. The result described in the source is process crash behavior. The supplied CVSS vector is AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating network reachability, low attack complexity, and availability impact without reported confidentiality or integrity impact.

Defensive priority

High — prioritize remediation because the issue is remotely reachable, requires no privileges or user interaction, and can crash the affected service. Treat it as especially important for exposed MES PC instances or any environment where the vulnerable web component is accessible from untrusted networks.

Recommended defensive actions

• Verify whether any MES PC installations still include the affected Apache HTTP Server/XAMPP component.
• Apply Festo’s replacement guidance: obtain the current Factory Control Panel version from Festo technical support at [email protected].
• Reduce exposure of the affected web service by limiting network access to trusted hosts and segmenting OT/ICS networks.
• Monitor for Apache process crashes, restarts, or unusual HTTP requests involving If: headers.
• Retire or isolate unsupported deployments that cannot be updated promptly.
• Follow CISA ICS defense-in-depth and recommended-practices guidance for industrial control environments.

Evidence notes

This debrief is based only on the supplied source corpus and official references. The core vulnerability description states that a crafted If: header can cause an out-of-bounds heap memory read or a single-byte zero write and may crash Apache HTTP Server 2.4.54 and earlier. The CISA CSAF source item (ICSA-26-027-02) republishes the Festo advisory context for Festo Didactic SE MES PC and includes a vendor remediation note directing users to a Factory Control Panel replacement. Published date context is 2024-02-27; later source revisions in the advisory history should not be treated as the CVE issue date.

Official resources