Overview
CVE-2025-26858 is a high-severity buffer overflow vulnerability affecting the Modbus TCP functionality of Socomec DIRIS Digiware M-70 version 1.6.9. This vulnerability allows an unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted network packets to the device. The vulnerability was published on 2025-12-01.
Technical Details
The vulnerability resides in the handling of Modbus TCP requests within the Socomec DIRIS Digiware M-70 1.6.9. A specifically crafted sequence of network packets can trigger a buffer overflow, overwriting critical memory regions and causing the device to crash or become unresponsive. The vulnerability is exploitable because the device doesn’t properly validate the size of the incoming data before writing it to a fixed-size buffer.
CVSS Analysis
- CVSS Score: 8.6 (HIGH)
- This score reflects the significant risk posed by this vulnerability, given its ease of exploitation (unauthenticated access) and the potential for a severe impact (denial of service) on critical industrial control systems.
Possible Impact
Successful exploitation of CVE-2025-26858 can lead to the following:
- Denial of Service (DoS): The primary impact is the disruption of the DIRIS Digiware M-70 device’s functionality, preventing it from providing essential monitoring and control data.
- Operational Disruption: In industrial environments where the DIRIS Digiware M-70 is used for critical monitoring or control, this DoS can lead to significant operational disruptions and potential safety hazards.
Mitigation and Patch Steps
Socomec has released a patch to address this vulnerability. Users of DIRIS Digiware M-70 version 1.6.9 are strongly advised to take the following steps:
- Apply the Patch: Immediately update the DIRIS Digiware M-70 firmware to the latest version provided by Socomec. Refer to the vendor’s security advisory for detailed instructions.
- Network Segmentation: Implement network segmentation to isolate the DIRIS Digiware M-70 device from untrusted networks.
- Access Control Lists (ACLs): Configure ACLs on network devices to restrict access to the DIRIS Digiware M-70 device to only authorized IP addresses and ports.
- Intrusion Detection/Prevention Systems (IDS/IPS): Deploy and configure IDS/IPS solutions to detect and block malicious Modbus TCP traffic.
- Regular Security Audits: Conduct regular security audits and vulnerability assessments to identify and address potential security weaknesses.
