Critical Vulnerability in Socomec DIRIS Digiware M-70: CVE-2025-55221 Puts Industrial Systems at Risk

Overview

A high-severity denial-of-service (DoS) vulnerability, identified as CVE-2025-55221, has been discovered in Socomec DIRIS Digiware M-70 version 1.6.9. This vulnerability allows an unauthenticated attacker to cause a denial of service condition by sending a specially crafted network packet via Modbus TCP over port 502. The flaw resides in the Modbus TCP and Modbus RTU over TCP USB Function functionality. This vulnerability necessitates immediate attention and mitigation measures to prevent potential disruptions to industrial control systems (ICS) and operational technology (OT) environments.

Technical Details

CVE-2025-55221 stems from improper handling of specific Modbus TCP requests within the Socomec DIRIS Digiware M-70 firmware. An attacker can exploit this by crafting a malicious Modbus TCP packet and sending it to the device on port 502. This specially crafted packet triggers a condition that causes the device to become unresponsive, leading to a denial of service. The vulnerability is exploitable without authentication, meaning any attacker with network access to the device can potentially trigger the DoS condition.

Specifically, the vulnerability lies in the device’s handling of unexpected or malformed data within the Modbus TCP message structure. The lack of robust input validation allows the crafted packet to overwhelm the device’s processing capabilities, ultimately leading to a system halt or crash.

Example Attack Scenario:

        # This is a conceptual example and not directly executable
        # It illustrates the type of crafted Modbus TCP packet that
        # could potentially trigger the vulnerability.
        # Actual exploitation may require more specific crafted data.

        import socket

        target_ip = "192.168.1.100"  # Replace with device IP
        target_port = 502

        # Craft the malicious Modbus TCP packet (example)
        # This is a simplified illustration, and the actual packet
        # structure will depend on the specific vulnerability details.
        malicious_packet = b"\x00\x01\x00\x00\x00\x06\x01\x03\x00\x00\x00\x01"

        # Send the packet
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.connect((target_ip, target_port))
            sock.sendall(malicious_packet)
            print(f"Malicious packet sent to {target_ip}:{target_port}")
        except Exception as e:
            print(f"Error: {e}")
        finally:
            sock.close()
        

CVSS Analysis

The Common Vulnerability Scoring System (CVSS) provides a standardized way to assess the severity of vulnerabilities. CVE-2025-55221 has been assigned a CVSS score of 8.6 (HIGH).

• CVSS Vector: (This would be dynamically populated based on the CVSS calculator and detailed analysis, assuming network attack vector and availability impact. A representative example would be: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
• Explanation: This score indicates a high severity due to the ease of exploitation (no authentication required, low attack complexity), and the significant impact on availability. A successful exploit can completely disrupt the device’s operation, potentially affecting critical industrial processes.

Possible Impact

The denial of service caused by CVE-2025-55221 can have significant consequences in industrial environments. Potential impacts include:

• Loss of monitoring and control: The affected device may cease to provide real-time data or respond to control commands, leading to a loss of visibility and control over critical processes.
• Process disruption: Inability to monitor or control processes can lead to disruptions, inefficiencies, or even safety hazards.
• Equipment damage: If the affected device is responsible for controlling critical equipment, the DoS condition could lead to equipment malfunction or damage.
• Safety incidents: In certain industrial settings, the loss of monitoring or control could create conditions that increase the risk of safety incidents.

Mitigation and Patch Steps

To mitigate the risk posed by CVE-2025-55221, the following steps are recommended:

• Apply the Patch: Socomec has likely released a firmware update to address this vulnerability. Immediately upgrade your DIRIS Digiware M-70 devices to the latest available firmware version. Refer to Socomec’s official website or support channels for the updated firmware.
• Network Segmentation: Isolate the affected devices on a separate network segment to limit the potential impact of a successful exploit. Implement firewalls and access control lists (ACLs) to restrict network access to the devices.
• Intrusion Detection/Prevention Systems (IDS/IPS): Deploy IDS/IPS solutions to monitor network traffic for malicious Modbus TCP packets. Configure these systems to alert or block suspicious activity.
• Rate Limiting: Implement rate limiting on Modbus TCP traffic to the affected devices to prevent an attacker from overwhelming the device with malicious requests.
• Disable Unnecessary Services: If possible, disable any unnecessary services or features on the Socomec DIRIS Digiware M-70 devices to reduce the attack surface.
• Vendor Communication: Stay informed about any updates, alerts, or advisories released by Socomec regarding this vulnerability.

References

• Talos Intelligence Vulnerability Report: https://talosintelligence.com/vulnerability_reports/TALOS-2025-2251
• NIST NVD CVE Entry: (Once available, the NIST NVD entry for CVE-2025-55221 will be linked here)
• Socomec Official Website: (Link to Socomec’s website where firmware updates are available – e.g., https://www.socomec.com/)