ESB-2026.5575

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.5575 ICS Advisory | ICSA-26-141-01 Hitachi Energy GMS600 22 May 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: Hitachi Energy GMS600 Publisher: ICS-CERT Operating System: Industrial Appliance Resolution: Patch/Upgrade CVE Names: CVE-2022-4304 Original Bulletin: https://www.cisa.gov/news-events/ics-advisories/icsa-26-141-01 Comment: CVSS (Max): 5.9 CVE-2022-4304 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N) CVSS Source: NIST Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N EPSS (Max): 0.2% (44th) CVE-2022-4304 2026-05-21 - --------------------------BEGIN INCLUDED TEXT-------------------- ICS Advisory (ICSA-26-141-01) Hitachi Energy GMS600 Release Date May 21, 2026 Related topics: Industrial Control System Vulnerabilities , Industrial Control Systems View CSAF Summary Hitachi Energy is aware of the vulnerability, CVE-2022-4304 in the OSS component OpenSSL, that affects the GMS600 versions that are listed below. An attacker successfully exploiting this vulnerability could send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection. For immediate mitigation /workaround information, please refer to the General Mitigation Factors/Workarounds The following versions of Hitachi Energy GMS600 are affected: o GMS600 vers:GMS600/>=1.3.0|<=1.3.1 (CVE-2022-4304) CVSS Vendor Equipment Vulnerabilities v3 5.9 Hitachi Energy Hitachi Energy GMS600 Observable Discrepancy Background o Critical Infrastructure Sectors: Critical Manufacturing o Countries/Areas Deployed: Worldwide o Company Headquarters Location: Switzerland --------------------------------------------------------------------------------- Vulnerabilities Expand All + CVE-2022-4304 A timing-based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE. For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a server could use this flaw to send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection. View CVE Details --------------------------------------------------------------------------------- Affected Products Hitachi Energy GMS600 Vendor: Hitachi Energy Product Version: GMS600 versions 1.3.0 and 1.3.1 Product Status: known_affected Remediations Vendor fix Upgrade to version 1.3.2 Relevant CWE: CWE-203 Observable Discrepancy --------------------------------------------------------------------------------- Metrics CVSS Version Base Score Base Vector String Severity 3.1 5.9 MEDIUM CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/ A:N --------------------------------------------------------------------------------- Acknowledgments o Hitachi Energy Internal Team reported this vulnerability to CISA --------------------------------------------------------------------------------- Notice The information in this document is subject to change without notice and should not be construed as a commitment by Hitachi Energy. Hitachi Energy provides no warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, for the information contained in this document, and assumes no responsibility for any errors that may appear in this document. In no event shall Hitachi Energy or any of its suppliers be liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, or from the use of any hardware or software described in this document, even if Hitachi Energy or its suppliers have been advised of the possibility of such damages. This document and parts hereof must not be reproduced or copied without written permission from Hitachi Energy and the contents hereof must not be imparted to a third party nor used for any unauthorized purpose. All rights to registrations and trademarks reside with their respective owners. --------------------------------------------------------------------------------- Support For additional information and support please contact your product provider or Hitachi Energy service organization. For contact information, see https:// www.hitachienergy.com/contact-us/ for Hitachi Energy contact-centers. --------------------------------------------------------------------------------- General Mitigation Factors Recommended security practices and firewall configurations such as enforcing ingress IP allowlisting and applying traffic rate limiting in accordance with the operational security policy can help protect a process control network from attacks that originate from outside the network. Such practices include that process control systems are physically protected from direct access by unauthorized personnel, have no direct connections to the Internet, and are separated from other networks by means of a firewall system that has a minimal number of ports exposed, and others that have to be evaluated case by case. 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. --------------------------------------------------------------------------------- SSVC SSVCv2/E:N/A:Y/2026-04-22T13:37:14Z/ --------------------------------------------------------------------------------- Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/ notification) and this Privacy & Use policy (https://www.cisa.gov/ privacy-policy). --------------------------------------------------------------------------------- Recommended Practices CISA recommends users take defensive measures to minimize the exploitation risk of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolate them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its 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. --------------------------------------------------------------------------------- Advisory Conversion Disclaimer This ICSA is a verbatim republication of Hitachi Energy PSIRT 8DBD000159 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact Hitachi Energy PSIRT directly for any questions regarding this advisory. Revision History o Initial Release Date: 2023-06-27 Date Revision Summary 2023-06-27 1 Initial public release. 2026-04-28 2 Updated fixed version. 2026-05-21 3 Initial CISA Republication of Hitachi Energy PSIRT 8DBD000159 advisory --------------------------------------------------------------------------------- Legal Notice and Terms of Use This product is provided subject to this Notification and this Privacy & Use policy. Vendor o Hitachi Energy - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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