1. EXECUTIVE SUMMARY

CVSS v4 7.1
ATTENTION: Low attack complexity
Vendor: Hitachi Energy
Equipment: Relion 670/650/SAM600-IO Series
Vulnerability: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

2. RISK EVALUATION

Successful exploitation of this vulnerability can allow an attacker to reboot the device and cause a denial-of-service condition.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Hitachi Energy reports the following products are affected:

Relion 670/650/SAM600-IO series: Versions 2.2.2.0 up to but not including 2.2.2.6
Relion 670/650/SAM600-IO series: Versions 2.2.3.0 up to but not including 2.2.3.7
Relion 670/650/SAM600-IO series: Versions 2.2.4.0 up to but not including 2.2.4.4
Relion 670/650/SAM600-IO series: Versions 2.2.5.6 up to but not including 2.2.5.6
Relion 670/650/SAM600-IO series: 2.2.0.x
Relion 670/650/SAM600-IO series: 2.2.1.x

3.2 VULNERABILITY OVERVIEW

3.2.1 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120

A vulnerability exists in the input validation of the GOOSE messages where out of range values received and processed by the IED cause a reboot of the device. In order for an attacker to exploit the vulnerability, GOOSE receiving blocks need to be configured.

CVE-2023-4518 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

A CVSS v4 score has also been calculated for CVE-2023-4518. A base score of 7.1 has been calculated; the CVSS vector string is (CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N).

3.3 BACKGROUND

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

3.4 RESEARCHER

Hitachi Energy PSIRT reported this vulnerability to CISA.

4. MITIGATIONS

Hitachi Energy identified the following specific workarounds and mitigations users can apply to reduce risk:

Relion 670 series Version 2.2.2.x up to but not including 2.2.2.6: Update to Version 2.2.2.6
Relion 670 series Version 2.2.3.x up to but not including 2.2.3.7: Update to Version 2.2.3.7
Relion 670/650 series Version 2.2.4.x up to but not including 2.2.4.4: Update to Version 2.2.4.4
Relion 670/650/SAM600-IO series Version 2.2.5.6 up to but not including 2.2.5.6: Update to Version 2.2.5.6
Relion 670 series Version 2.2.0 all revisions and Relion 670/650/SAM600-IO series Version 2.2.1 all revisions: Apply general mitigations.

For more information see the associated Hitachi Energy PSIRT security advisory 8DBD000170 Cybersecurity Advisory - Improper Input Validation Vulnerability in Hitachi Energy's Relion® 670/650/SAM600-IO series Product.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as:

Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the Internet.
Locate control system networks and remote devices behind firewalls and isolating them from business networks.
When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices.

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 cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

Do not click web links or open attachments in unsolicited email messages.
Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.

5. UPDATE HISTORY

May 13, 2025: Initial Republication of Hitachi Energy Advisory 8DBD000170