CVE-2025-5023 is a high-severity vulnerability affecting Mitsubishi Electric Corporation's photovoltaic system monitor models PV-DR004J and PV-DR004JA, encompassing all versions of these discontinued products. The vulnerability arises from the use of hard-coded credentials (CWE-798) embedded within the product firmware, which can be exploited by an attacker within Wi-Fi communication range between the measurement unit and the display unit. By leveraging these hard-coded user ID and password pairs—obtainable through exploitation of a related vulnerability CVE-2025-5022—an attacker can gain unauthorized access to the system. This access enables the attacker to disclose sensitive information such as generated power metrics and electricity sold back to the grid, tamper with or destroy stored or configured data, or induce a Denial-of-Service (DoS) condition, severely impacting system availability and integrity. Notably, the vulnerability is mitigated when the device enters power-saving mode after 5 minutes of inactivity, turning off the display unit's LCD screen, which disables Wi-Fi communication. However, since the products were discontinued in 2015 and support ended in 2020, no official patches or updates are available to remediate this issue. The CVSS v3.1 base score of 7.1 reflects the high impact on integrity and availability, with attack vector being adjacent network (Wi-Fi), requiring no privileges or user interaction but with high attack complexity due to the need to exploit CVE-2025-5022 first. The vulnerability poses a significant risk to the confidentiality, integrity, and availability of photovoltaic monitoring systems, potentially affecting energy management and operational continuity in installations using these devices.

For European organizations, especially those involved in renewable energy generation and management, this vulnerability presents a tangible risk. Unauthorized disclosure of power generation and grid feed-in data could lead to privacy breaches or competitive intelligence gathering. More critically, tampering or destruction of configuration and stored data can disrupt energy monitoring and reporting, potentially causing operational inefficiencies or regulatory non-compliance. A Denial-of-Service condition could interrupt real-time monitoring, impairing the ability to detect faults or optimize energy production. Given the increasing reliance on photovoltaic systems for sustainable energy goals across Europe, compromised monitoring devices could undermine energy management strategies and grid stability. Additionally, attackers could leverage this vulnerability as a foothold for lateral movement within industrial or energy sector networks, escalating the threat landscape. The lack of vendor support and patches exacerbates the risk, as affected organizations must rely on compensating controls or device replacement to mitigate exposure.

Since no patches are available due to product discontinuation and support cessation, European organizations should prioritize the following specific mitigations: 1) Identify and inventory all installations using PV-DR004J and PV-DR004JA devices to assess exposure. 2) Physically isolate or segment the Wi-Fi communication network between measurement and display units to restrict attacker proximity, employing network segmentation and strong Wi-Fi security measures such as WPA3 with robust passphrases. 3) Disable Wi-Fi communication where feasible or reduce the Wi-Fi signal range through antenna adjustments or shielding to limit attacker access. 4) Implement strict monitoring of network traffic between units to detect anomalous access attempts or data exfiltration indicative of exploitation. 5) Where possible, replace affected devices with supported, updated photovoltaic monitoring systems that do not contain hard-coded credentials and receive security updates. 6) Train operational staff to recognize signs of device tampering or malfunction that may indicate exploitation. 7) Incorporate this vulnerability into risk assessments and incident response plans to ensure preparedness. These targeted actions go beyond generic advice by focusing on compensating controls tailored to the unique constraints of unsupported legacy hardware in critical energy infrastructure.