Mitsubishi Electric MELSEC iQ-F Series (Update A)

1. EXECUTIVE SUMMARY

• CVSS v3 7.5
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Mitsubishi Electric

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• Equipment: MELSEC iQ-F, iQ-R, Q, and L series

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• Vulnerability: Plaintext Storage of Password

2. UPDATE OR REPOSTED INFORMATION

This updated advisory is a follow-up to the original advisory titled ICSA-23-061-01 Mitsubishi Electric MELSEC iQ-F Series that was published March 02, 2023, on the ICS webpage on cisa.gov/ICS.

3. RISK EVALUATION

Successful exploitation of this vulnerability could allow an unauthenticated attacker to login to an FTP server or web server by obtaining plaintext credentials stored in project files.

4. TECHNICAL DETAILS

4.1 AFFECTED PRODUCTS

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The following Mitsubishi Electric MELSEC products are affected:

• MELSEC iQ-F FX5U(C) CPU modules: All models, all versions
• MELSEC iQ-F FX5UJ CPU modules: All models, all versions
• MELSEC iQ-F FX5S CPU modules: All models, all versions
• MELSEC iQ-F FX5-ENET: All versions
• MELSEC iQ-F FX5-ENET/IP: All versions
• MELSEC iQ-R R00/01/02CPU: All versions
• MELSEC iQ-R R04/08/16/32/120(EN)CPU: All versions
• MELSEC iQ-R R08/16/32/120SFCPU: All versions
• MELSEC iQ-R R08/16/32/120PCPU: All versions
• MELSEC iQ-R R08/16/32/120PSFCPU: All versions
• MELSEC iQ-R RJ71EN71: All versions
• MELSEC iQ-R R12CCPU-V: All versions
• MELSEC-Q Q03UDECPU, Q04/06/10/13/20/26/50/100UDEHCPU: All versions
• MELSEC-Q Q03/04/06/13/26UDVCPU: All versions
• MELSEC-Q Q04/06/13/26UDPVCPU: All versions
• MELSEC-Q QJ71E71-100: All versions
• MELSEC-L L02/06/26CPU(-P), L26CPU-(P)BT: All versions
• MELSEC-L LJ71E71-100: All versions

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4.2 VULNERABILITY OVERVIEW

4.2.1 PLAINTEXT STORAGE OF A PASSWORD CWE-256 

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Mitsubishi Electric MELSEC iQ-F, iQ-R, Q, and L series are vulnerable to an information disclosure vulnerability due to plaintext storage of a password.

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CVE-2023-0457 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

4.3 BACKGROUND

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

4.4 RESEARCHER

JeongHoon Bae, YiJoon Jung, JinYoung Kim, HyeokJong Yun and HeeA Go of HelloT reported this vulnerability to Mitsubishi Electric.

5. MITIGATIONS

Mitsubishi Electric recommends that customers take the following mitigation measures to minimize the risk of exploiting this vulnerability:

• Encrypt the communication data or project files when sending and receiving or sharing these files.
• 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.

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• Restrict physical access to affected products.
• For MELSEC iQ-F or iQ-R series, use an IP filter function to block access from untrusted hosts.

For details on the IP filter function, please refer to the following manuals for each product;

"12.1 IP Filter Function" in the MELSEC iQ-F FX5 User's Manual (Ethernet Communication)

"1.13 Security" - "IP filter" in the MELSEC iQ-R Ethernet User’s Manual (Application).

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For specific update instructions and additional details see the Mitsubishi Electric 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 at 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.

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 exploits specifically target this vulnerability.

• Mitsubishi Electric