CVE-2022-29492 is a medium-severity vulnerability affecting Hitachi Energy's MicroSCADA Pro SYS600 (up to version 9.4 FP2 Hotfix 4) and MicroSCADA X SYS600 (versions 10 through 10.3.1). The vulnerability arises from improper input validation (CWE-20) in the handling of malformed IEC 104 TCP packets. IEC 60870-5-104 (IEC 104) is a protocol widely used in supervisory control and data acquisition (SCADA) systems for electric power systems, enabling communication between control centers and substations. In this case, when the affected MicroSCADA products receive a malformed IEC 104 TCP packet, the packet is dropped as expected; however, the TCP connection remains open. This behavior can be exploited by an attacker to cause a denial-of-service (DoS) condition by exhausting available TCP connections or resources, potentially disrupting communication between control systems and field devices. The vulnerability does not require authentication or user interaction and can be triggered remotely over the network, increasing its risk profile. The CVSS v3.1 score is 5.3 (medium), reflecting the network attack vector, low complexity, no privileges required, no user interaction, and impact limited to availability (denial of service). No known exploits are currently reported in the wild, and no patches are explicitly linked in the provided data, though newer versions beyond 10.3.1 may have addressed the issue. This vulnerability is particularly relevant for critical infrastructure environments where Hitachi Energy's MicroSCADA systems are deployed to monitor and control electrical grids, as disruption could impact operational continuity and grid stability.

For European organizations, especially those operating critical energy infrastructure such as power generation, transmission, and distribution, this vulnerability poses a risk of service disruption. A successful exploitation could lead to denial-of-service conditions on SCADA communication channels, potentially delaying or blocking control commands and status updates between control centers and substations. This could degrade situational awareness and operational response capabilities, increasing the risk of outages or unsafe operating conditions. Given the essential role of SCADA systems in managing electrical grids, even temporary denial-of-service events could have cascading effects on energy supply reliability. Additionally, attackers could leverage this vulnerability as part of a broader attack chain targeting industrial control systems (ICS), potentially as a distraction or to degrade defenses. The medium severity and lack of known exploits suggest the threat is currently moderate but warrants proactive mitigation due to the critical nature of affected systems and the potential impact on European energy infrastructure.

1. Upgrade: Organizations should promptly upgrade MicroSCADA Pro SYS600 and MicroSCADA X SYS600 to versions later than 9.4 FP2 Hotfix 4 and 10.3.1 respectively, once patches or fixed versions are available from Hitachi Energy. 2. Network Segmentation: Isolate SCADA networks from general enterprise networks and restrict access to IEC 104 communication ports using firewalls and network access controls to limit exposure to untrusted sources. 3. Traffic Validation: Deploy deep packet inspection or protocol-aware intrusion detection/prevention systems (IDS/IPS) capable of validating IEC 104 traffic to detect and block malformed packets before they reach vulnerable SCADA devices. 4. Connection Limits: Configure network devices and SCADA systems to limit the number of simultaneous TCP connections per source IP to prevent resource exhaustion from malformed packet attacks. 5. Monitoring and Logging: Implement enhanced monitoring of IEC 104 traffic and TCP connection states on SCADA systems to detect abnormal connection patterns or repeated malformed packet attempts. 6. Incident Response Preparedness: Develop and test response plans for denial-of-service events affecting SCADA communications, ensuring rapid recovery and fallback procedures. 7. Vendor Coordination: Maintain communication with Hitachi Energy for official patches, advisories, and support related to this vulnerability and other emerging threats.