Hitachi Energy Relion 670/650/SAM600-IO

1. EXECUTIVE SUMMARY

• CVSS v3 8.1
• Vendor: Hitachi Energy
• Equipment: Relion 670/650/SAM600-IO
• Vulnerability: Insecure Default Initialization of Resource

2. RISK EVALUATION

Successful exploitation of this vulnerability could hijack existing TCP sessions to inject packets of their choosing or cause denial-of-service conditions.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Hitachi Energy reports this vulnerability affects the following Relion products:

• Relion 670/650 series: All revisions of Version 2.2.0
• Relion 670/650/SAM600-IO series: All revisions of Version 2.2.1
• Relion 670 series: All revisions of Version 2.2.2
• Relion 670 series: All revisions of Version 2.2.3 until 2.2.3.3
• Relion 670/650 series: All revisions of Version 2.2.4

3.2 VULNERABILITY OVERVIEW

3.2.1    INSECURE DEFAULT INITIALIZATION OF RESOURCE CWE-1188

A vulnerability exists in the early boot process of the product in which there is a tiny time gap where a previous version of VxWorks is loaded prior to booting up the complete application firmware. The older version of VxWorks is susceptible to Urgent/11, which may allow for remote code execution on the device before the operating system is loaded.

CVE-2021-35535 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is (AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Energy
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Switzerland

3.4 RESEARCHER

A Department of Energy CyTRICS researcher from Idaho National Laboratory reported this vulnerability to Hitachi Energy.

4. MITIGATIONS

Hitachi Energy recommends the following actions to mitigate this vulnerability:

• Relion 670/650 series Version 2.2.0: Upgrade to Version 2.2.5
• Relion 670/650/SAM600-IO series Version 2.2.1: Upgrade to Version 2.2.5
• Relion 670 series Version 2.2.2: Upgrade to Version 2.2.5
• Relion 670 series Version 2.2.3: Update to Revision 2.2.3.4 or upgrade to Version 2.2.5
• Relion 670/650 series Version 2.2.4: Upgrade to Version 2.2.5

Hitachi Energy recommends the following security practices and firewall configurations to help protect process control networks from attacks that originate from outside the network:

• Physically protect process control systems from direct access by unauthorized personnel.
• Do not directly connect to the Internet.
• Separate from other networks by means of a firewall system that has a minimal number of ports exposed.
• Process control systems should not be used for Internet surfing, instant messaging, or receiving e-mails. 
• Portable computers and removable storage media should be carefully scanned for viruses before they are connected to a control system.

Please see Hitachi Energy advisory 8DBD000061 for additional mitigation and update information.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.



CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.



Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. This vulnerability has a high attack complexity.