CVE-2025-55221

High

Published: 01 December 2025

Published

01 December 2025

Modified

05 December 2025

KEV Added

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Patch

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CVSS Score v3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Score 0.0008 23.6th percentile

Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-55221 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Socomec Diris M-70 Firmware. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 23.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-41 (Port and I/O Device Access) and SC-5 (Denial-of-service Protection).

Deeper analysis

CVE-2025-55221 is a denial of service vulnerability affecting the Modbus TCP and Modbus RTU over TCP USB Function functionality in Socomec DIRIS Digiware M-70 version 1.6.9. The issue arises from a specially crafted network packet that triggers a denial of service condition. This vulnerability is specific to malicious messages sent via Modbus TCP over port 502 and is associated with CWE-306 (Missing Authentication for Critical Function). It received a CVSS v3.1 base score of 8.6 (AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H).

Any attacker with network access to the affected device can exploit this vulnerability by sending an unauthenticated packet over port 502, leading to a denial of service that impacts availability without requiring privileges, user interaction, or authentication.

Mitigation details are available in the Talos Intelligence advisory at https://talosintelligence.com/vulnerability_reports/TALOS-2025-2251.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2025-200036

Vulnerability details

A denial of service vulnerability exists in the Modbus TCP and Modbus RTU over TCP USB Function functionality of Socomec DIRIS Digiware M-70 1.6.9. A specially crafted network packet can lead to a denial of service. An attacker can send…

an unauthenticated packet to trigger this vulnerability.This vulnerability is specific to the malicious message sent via Modbus TCP over port 502.

CWE(s): CWE-306

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.

attack.mitre.org →

Why these techniques?

The vulnerability allows unauthenticated remote attackers to send a specially crafted packet over port 502, exploiting the Modbus TCP service to trigger a denial of service, directly mapping to application exploitation for endpoint DoS.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0