Mitsubishi Electric MELSEC iQ-F Series CPU Module

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1. EXECUTIVE SUMMARY

• CVSS v4 6.9
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Mitsubishi Electric
• Equipment: MELSEC iQ-F Series CPU module
• Vulnerability: Missing Authentication for Critical Function

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to read or write the device values of the product. In addition, the attacker may be able to stop the operation of the programs.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Mitsubishi Electric reports the following versions of MELSEC iQ-F Series are affected:

• MELSEC iQ-F Series FX5U-32MT/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-32MT/DS: 1.060 and later
• MELSEC iQ-F Series FX5U-32MT/ESS: 1.060 and later
• MELSEC iQ-F Series FX5U-32MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5U-64MT/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-64MT/DS: 1.060 and later
• MELSEC iQ-F Series FX5U-64MT/ESS: 1.060 and later
• MELSEC iQ-F Series FX5U-64MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5U-80MT/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-80MT/DS: 1.060 and later
• MELSEC iQ-F Series FX5U-80MT/ESS: 1.060 and later
• MELSEC iQ-F Series FX5U-80MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5U-32MR/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-32MR/DS: 1.060 and later
• MELSEC iQ-F Series FX5U-64MR/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-64MR/DS: 1.060 and later
• MELSEC iQ-F Series FX5U-80MR/ES: 1.060 and later
• MELSEC iQ-F Series FX5U-80MR/DS: 1.060 and later
• MELSEC iQ-F Series FX5UC-32MT/D: 1.060 and later
• MELSEC iQ-F Series FX5UC-32MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5UC-64MT/D: 1.060 and later
• MELSEC iQ-F Series FX5UC-64MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5UC-96MT/D: 1.060 and later
• MELSEC iQ-F Series FX5UC-96MT/DSS: 1.060 and later
• MELSEC iQ-F Series FX5UC-32MT/DS-TS: 1.060 and later
• MELSEC iQ-F Series FX5UC-32MT/DSS-TS: 1.060 and later
• MELSEC iQ-F Series FX5UC-32MR/DS-TS: 1.060 and later
• MELSEC iQ-F Series FX5UJ-24MT/ES: All versions
• MELSEC iQ-F Series FX5UJ-24MT/DS: All versions
• MELSEC iQ-F Series FX5UJ-24MT/ESS: All versions
• MELSEC iQ-F Series FX5UJ-24MT/DSS: All versions
• MELSEC iQ-F Series FX5UJ-40MT/ES: All versions
• MELSEC iQ-F Series FX5UJ-40MT/DS: All versions
• MELSEC iQ-F Series FX5UJ-40MT/ESS: All versions
• MELSEC iQ-F Series FX5UJ-40MT/DSS: All versions
• MELSEC iQ-F Series FX5UJ-60MT/ES: All versions
• MELSEC iQ-F Series FX5UJ-60MT/DS: All versions
• MELSEC iQ-F Series FX5UJ-60MT/ESS: All versions
• MELSEC iQ-F Series FX5UJ-60MT/DSS: All versions
• MELSEC iQ-F Series FX5UJ-24MR/ES: All versions
• MELSEC iQ-F Series FX5UJ-24MR/DS: All versions
• MELSEC iQ-F Series FX5UJ-40MR/ES: All versions
• MELSEC iQ-F Series 'FX5UJ-40MR/DS: All versions
• MELSEC iQ-F Series FX5UJ-60MR/ES: All versions
• MELSEC iQ-F Series FX5UJ-60MR/DS: All versions
• MELSEC iQ-F Series FX5UJ-24MT/ES-A: All versions
• MELSEC iQ-F Series FX5UJ-24MR/ES-A: All versions
• MELSEC iQ-F Series FX5UJ-40MT/ES-A: All versions
• MELSEC iQ-F Series FX5UJ-40MR/ES-A: All versions
• MELSEC iQ-F Series FX5UJ-60MT/ES-A: All versions
• MELSEC iQ-F Series FX5UJ-60MR/ES-A: All versions
• MELSEC iQ-F Series FX5S-30MT/ES: All versions
• MELSEC iQ-F Series FX5S-30MT/DS: All versions
• MELSEC iQ-F Series FX5S-30MT/ESS: All versions
• MELSEC iQ-F Series FX5S-30MT/DSS: All versions
• MELSEC iQ-F Series FX5S-40MT/ES: All versions
• MELSEC iQ-F Series FX5S-40MT/DS: All versions
• MELSEC iQ-F Series FX5S-40MT/ESS: All versions
• MELSEC iQ-F Series FX5S-40MT/DSS: All versions
• MELSEC iQ-F Series FX5S-60MT/ES: All versions
• MELSEC iQ-F Series FX5S-60MT/DS: All versions
• MELSEC iQ-F Series FX5S-60MT/ESS: All versions
• MELSEC iQ-F Series FX5S-60MT/DSS: All versions
• MELSEC iQ-F Series FX5S-80MT/ES: All versions
• MELSEC iQ-F Series FX5S-80MT/DS: All versions
• MELSEC iQ-F Series FX5S-80MT/ESS: All versions
• MELSEC iQ-F Series FX5S-80MT/DSS: All versions
• MELSEC iQ-F Series FX5S-30MR/ES: All versions
• MELSEC iQ-F Series FX5S-30MR/DS: All versions
• MELSEC iQ-F Series FX5S-40MR/ES: All versions
• MELSEC iQ-F Series FX5S-40MR/DS: All versions
• MELSEC iQ-F Series FX5S-60MR/ES: All versions
• MELSEC iQ-F Series FX5S-60MR/DS: All versions
• MELSEC iQ-F Series FX5S-80MR/ES: All versions
• MELSEC iQ-F Series FX5S-80MR/DS: All versions

3.2 VULNERABILITY OVERVIEW

3.2.1 MISSING AUTHENTICATION FOR CRITICAL FUNCTION CWE-306

An information disclosure, information tampering, and denial-of-service vulnerability exists in MELSEC iQ-F series CPU module due to missing authentication for critical function. Since MODBUS/TCP in the products does not have authentication features, an attacker may be able to read or write the device values of the product. In addition, the attacker may be able to stop the operation of the programs.

CVE-2025-7405 has been assigned to this vulnerability. A CVSS v3.1 base score of 7.3 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

A CVSS v4 score has also been calculated for CVE-2025-7405. A base score of 6.9 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Japan

3.4 RESEARCHER

Thai Do, Minh Pham, Quan Le and Loc Nguyen of Unit 515, OPSWAT reported this vulnerability to Mitsubishi Electric.

4. MITIGATIONS

Mitsubishi Electric Corporation advises that there are no plans to release a fixed version. Mitsubishi Electric recommends users take the following mitigation measures to minimize the risk of vulnerability exploit:

• Use a firewall or virtual private network (VPN), etc. to prevent unauthorized access when internet access is required.
• Use within a LAN and block access from untrusted networks and hosts through firewalls.
• Use IP filter function to block access from untrusted hosts. For details on the IP filter function, please refer to the following manual for each product.
  "13.1 IP Filter Function" in the MELSEC iQ-F FX5 User's Manual (Communication) Please download the manual from the following URL.
  https://www.mitsubishielectric.com/fa/download/index.html
• Restrict physical access to the affected products and the LAN that is connected by them.

Mitsubishi Electric Corporation recommends users contact their local Mitsubishi Electric representative with questions.

For more information, see Mitsubishi Electric's security advisory.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.

5. UPDATE HISTORY

• August 28, 2025: Initial Republication of Mitsubishi Electric 2025-011

• Mitsubishi Electric