Hitachi Energy GMS600 Vulnerable to OpenSSL Timing Side Channel (CVE-2022-4304)

Runtime Rebel is issuing an advisory regarding a significant vulnerability, CVE-2022-4304, affecting Hitachi Energy GMS600 devices used within Critical Manufacturing sectors globally. This vulnerability, a timing-based side channel in OpenSSL’s RSA Decryption implementation, could enable attackers to decrypt sensitive application data. Security professionals operating industrial control systems (ICS) or supervisory control and data acquisition (SCADA) environments should prioritize mitigation to safeguard operational integrity and data confidentiality, according to CISA ICSA-26-141-01.

Technical Analysis of CVE-2022-4304

CVE-2022-4304 describes an observable discrepancy, classified as CWE-203. This flaw exists within the OpenSSL RSA Decryption implementation, specifically presenting as a timing-based side channel. This type of vulnerability allows for a Bleichenbacher style attack, where an attacker can infer information about encrypted data by observing variations in the time it takes for a system to process different inputs. In the context of this specific OpenSSL timing side channel exploit, the vulnerability affects all RSA padding modes, including PKCS#1 v1.5, RSA-OEAP, and RSASVE.

For a successful exploit, an adversary must be able to send a substantial volume of trial messages to the server. By carefully monitoring the processing times of these messages, the attacker can recover the pre-master secret used for the original TLS connection. Once the pre-master secret is compromised, the attacker can then decrypt the application data transmitted over that connection, undermining the confidentiality of communications. This TTP is particularly concerning for systems handling proprietary manufacturing processes or sensitive operational data.

Affected Products and Scope

The vulnerability specifically impacts Hitachi Energy GMS600 versions 1.3.0 and 1.3.1. The GMS600, a key component in various industrial operations, is deployed worldwide, making the potential impact geographically broad. While the CVSS v3.1 base score for CVE-2022-4304 is 5.9 (Medium), its presence in Critical Manufacturing environments elevates the risk due to the potential for operational disruption and intellectual property theft. Attack complexity is rated ‘High’ due to the need for a large number of trial messages, but the consequences of successful exploitation are significant.

Actionable Recommendations: How to Mitigate CVE-2022-4304

Organizations operating Hitachi Energy GMS600 devices must prioritize remediation efforts to address CVE-2022-4304. The primary and most effective mitigation is to upgrade affected systems.

• Vendor Fix: Upgrade all Hitachi Energy GMS600 installations currently running versions 1.3.0 or 1.3.1 to version 1.3.2. This update contains the necessary patch to resolve the OpenSSL timing side channel vulnerability. This is the critical Hitachi Energy GMS600 1.3.0 1.3.1 patch guidance.

Beyond the immediate patch, general security best practices for ICS environments are essential for comprehensive defense:

• Network Segmentation: Isolate control system networks and remote devices behind firewalls. Ensure these systems have no direct connection to the internet and are separated from business networks to limit exposure.
• Access Control: Enforce strict ingress IP allowlisting and apply traffic rate limiting in accordance with operational security policies. Process control systems should be physically protected from unauthorized access.
• Secure Remote Access: When remote access is indispensable, utilize secure methods such as Virtual Private Networks (VPNs). However, recognize that VPNs can have their own vulnerabilities and must be kept up-to-date. A VPN’s security is only as strong as its connected devices.
• Endpoint Security: Implement robust endpoint protection. Portable computers and removable storage media connected to control systems must be meticulously scanned for malware and viruses.
• System Usage Policy: Restrict the use of process control systems for non-operational activities, such as internet browsing, instant messaging, or email, to minimize attack vectors.
• Monitoring and Detection: Continuously monitor network traffic and system logs for anomalous behavior that could indicate attempted exploitation. Implement a robust SIEM solution integrated with EDR tools in the operational technology (OT) environment where feasible, alongside regular vulnerability assessments.

Security teams should conduct a thorough impact analysis and risk assessment before deploying any defensive measures to ensure operational continuity. Proactive defense of ICS assets requires a multi-layered approach, aligning with frameworks like MITRE ATT&CK for ICS to identify and counter potential TTPs.