CVE-2025-20085 identifies a critical security flaw in the Socomec DIRIS Digiware M-70, specifically version 1.6.9, related to the Modbus RTU over TCP protocol implementation. The vulnerability stems from missing authentication controls on critical functions, classified under CWE-306. An attacker can send a specially crafted network packet without any authentication or user interaction to trigger a denial of service condition on the device. Furthermore, this attack can weaken the device's credential management, causing it to revert to default documented credentials, which are publicly known and thus easily exploitable. The vulnerability impacts confidentiality and integrity by allowing unauthorized access and potential manipulation of device settings, although availability impact is limited to denial of service without permanent device damage. The CVSS 3.1 base score is 7.2 (high), reflecting the network attack vector, low attack complexity, no privileges or user interaction required, and a scope change due to credential weakening. The device affected is used in industrial environments for power monitoring and management, making it a critical component in operational technology (OT) networks. No patches have been published yet, and no exploits are known in the wild, but the vulnerability's characteristics suggest a high risk if left unmitigated.

For European organizations, especially those in industrial, energy, and critical infrastructure sectors, this vulnerability poses a significant threat. The Socomec DIRIS Digiware M-70 is commonly deployed in power monitoring and energy management systems, which are integral to operational continuity and safety. Exploitation could lead to denial of service, disrupting monitoring capabilities and potentially causing operational blind spots. More critically, the fallback to default credentials could allow attackers to gain unauthorized access, manipulate device configurations, or pivot within OT networks, increasing the risk of broader industrial control system compromise. This could result in data integrity issues, operational disruptions, and increased risk of safety incidents. Given Europe's strong regulatory environment around critical infrastructure security (e.g., NIS Directive), failure to address this vulnerability could also lead to compliance violations and reputational damage.

Since no official patch is currently available, European organizations should implement compensating controls immediately. These include strict network segmentation to isolate DIRIS Digiware M-70 devices from untrusted networks, especially restricting Modbus RTU over TCP traffic to trusted management stations only. Deploy network intrusion detection systems (NIDS) with signatures or anomaly detection tuned for Modbus protocol misuse to identify and block suspicious packets. Enforce strong access controls and authentication at the network perimeter and within OT environments. Change default credentials on all devices and audit for any devices that may have reverted to default credentials due to this vulnerability. Engage with Socomec for firmware updates or security advisories and plan for timely patch deployment once available. Additionally, implement continuous monitoring and incident response plans focused on OT assets to quickly detect and respond to exploitation attempts.