CVE-2021-35535: Hitachienergy Relion 650 Firmware

High severity, CVSS 8.1. EPSS: 0.7% chance of exploitation in the next 30 days.

Insecure Boot Image vulnerability in Hitachi Energy Relion Relion 670/650/SAM600-IO series allows an attacker who manages to get access to the front network port and to cause a reboot sequences of the device may exploit the vulnerability, where there is a tiny time gap during the booting process where an older version of VxWorks is loaded prior to application firmware booting, could exploit the vulnerability in the older version of VxWorks and cause a denial-of-service on the product. This issue affects: Hitachi Energy Relion 670 Series 2.2.2 all revisions; 2.2.3 versions prior to 2.2.3.3. Hitachi Energy Relion 670/650 Series 2.2.0 all revisions; 2.2.4 all revisions. Hitachi Energy Relion 670/650/SAM600-IO 2.2.1 all revisions.

Affected products

• Hitachienergy Relion 650 Firmware: version 2.2.0 only; version 2.2.1 only; version 2.2.4 only
• Hitachienergy Relion 670 Firmware: from 2.2.3, up to and including 2.2.3.3; version 2.2.0 only; version 2.2.1 only; version 2.2.2 only; version 2.2.4 only
• Hitachienergy Relion SAM600-Io Firmware: version 2.2.1 only

Published 2021-11-18. Last modified 2026-06-17.