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PatchSiren cyber security CVE debrief

CVE-2015-2787 Festo Didactic SE CVE debrief

CVE-2015-2787 is a critical PHP use-after-free vulnerability that can allow remote code execution when crafted data reaches unserialize handling. The supplied CISA CSAF source republishes the issue in the context of Festo Didactic SE MES PC and points to a vendor replacement/fix path.

Vendor
Festo Didactic SE
Product
MES PC
CVSS
CRITICAL 9.8
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

Security teams responsible for PHP deployments in the affected 5.4.x, 5.5.x, and 5.6.x branches, and operators of Festo Didactic SE MES PC systems that rely on the vendor-provided software stack referenced in the source advisory.

Technical summary

The advisory describes a use-after-free in process_nested_data within ext/standard/var_unserializer.re. A crafted unserialize call that interacts with unset inside an __wakeup function can trigger memory corruption, which the source characterizes as remotely exploitable code execution risk. The supplied CVSS vector is CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Defensive priority

Critical

Recommended defensive actions

  • Upgrade PHP to a fixed release at or above 5.4.39, 5.5.23, or 5.6.7, depending on your branch.
  • For Festo Didactic SE MES PC environments, obtain the current Factory Control Panel package from Festo technical support as described in the source remediation.
  • Inventory applications and services that call unserialize on untrusted data and remove or isolate that attack surface where possible.
  • Prioritize exposed systems for validation, patching, and regression testing, especially any systems reachable over untrusted networks.

Evidence notes

The source corpus identifies CVE-2015-2787 as a PHP use-after-free in process_nested_data and rates it CVSS 3.0 9.8. The CISA CSAF source item is a republication dated 2024-02-27 and revised 2026-01-27; it maps the advisory to Festo Didactic SE MES PC and includes a vendor remediation to replace XAMPP with the current Factory Control Panel. The supplied enrichment does not mark the CVE as KEV.

Sources and references

Verified primary and authoritative sources

  • CVE-2015-2787 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2015-2787

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

  • CVE-2015-2787 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2015-2787

    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.