CVE-2024-8176 Red Hat CVE debrief

Who should care

OT/ICS asset owners, operators, and maintainers using Hitachi Energy RTU500 series CMU Firmware with IEC61850 enabled should prioritize this advisory, along with integrators and incident responders supporting those environments.

Technical summary

The source description says libexpat can recurse indefinitely while processing deeply nested XML entity references, exhausting stack space and causing a crash. The supplied advisory frames the impact as denial of service and notes that memory corruption may be exploitable in some environments, depending on how the library is used. The recorded CVSS v3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, and the issue is stated to apply only if IEC61850 functionality is configured. Affected firmware ranges in the advisory are 12.7.1 through 12.7.7, 13.5.1 through 13.5.4, 13.6.1 through 13.6.2, 13.7.1 through 13.7.7, and 13.8.1; listed remediations include 12.7.8, 13.7.8 or later, and 13.8.2.

Defensive priority

High for any deployment of the affected RTU500 CMU Firmware where IEC61850 is enabled; otherwise, this advisory is not applicable. Treat as a priority patching item for OT environments because the documented effect is service disruption and the source allows for worse outcomes in some usage contexts.

Recommended defensive actions

• Confirm whether IEC61850 functionality is enabled on RTU500 series CMU Firmware assets before triaging exposure.
• Inventory CMU Firmware versions and compare them against the affected ranges listed in the advisory.
• Update to the vendor-fixed release that matches the installed branch: 12.7.8, 13.7.8 or later, or 13.8.2.
• If immediate patching is not possible, follow the vendor’s general mitigation factors/workarounds cited by CISA.
• Schedule changes through OT maintenance processes and validate operational impact before deployment.
• Monitor for crashes or abnormal parser behavior in XML/IEC61850-related workflows until remediation is complete.

Evidence notes

The debrief is based only on the supplied CISA CSAF advisory record (ICSA-26-062-03) and the linked official references. The advisory text explicitly states the libexpat recursive-entity stack overflow description, the IEC61850 configuration condition, the affected firmware ranges, and the remediation versions. The source corpus also includes a low-confidence vendor metadata mapping that is inconsistent ('vendorName' is 'Unknown Vendor' while the product is listed as Hitachi Energy), so product identification here follows the advisory title and affected-product fields rather than the vendor confidence label.

Official resources