Mitsubishi Electric CNC Series

1. EXECUTIVE SUMMARY CVSS v3 9.8 ATTENTION: Exploitable remotely/low attack complexity Vendor: Mitsubishi Electric Equipment: CNC Series devices Vulnerability: Classic Buffer Overflow
2. RISK EVALUATION Successful exploitation of this vulnerability could allow a malicious remote attacker to cause a denial-of-service condition and execute malicious code on the product by sending specially crafted packets. System reset is required for recovery.
3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following Mitsubishi Electric CNC series products are affected: M8V Series

M800VW (BND-2051W000-): All versions M800VS (BND-2052W000-): All versions M80V (BND-2053W000-): All versions M80VW (BND-2054W000-): All Versions

M8 Series

M800W (BND-2005W000-): All versions M800S (BND-2006W000-): All versions M80 (BND-2007W000-): All versions M80W (BND-2008W000-): All versions E80 (BND-2009W000-**): All versions

C80

C80 C80 (BND-2036W000-): All Versions M7V Series M700VW (BND-1012W000-): All versions M700VS (BND-1015W000-): All versions M70V (BND-1018W000-): All versions E70 (BND-1022W000-**): All versions

IoT Unit

Remote Service Gateway Unit (BND-2041W001-): All versions Data Acquisition Unit BND-2041W002-): All versions

3.2 VULNERABILITY OVERVIEW 3.2.1 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT (‘CLASSIC BUFFER OVERFLOW’) CWE-120 In all versions of Mitsubishi Electric CNC series devices, a malicious remote attacker could cause a denial-of-service condition and execute malicious code by sending specially crafted packets. CVE-2023-3346 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: Japan 3.4 RESEARCHER 01dGu0 of Zhejiang Qian Information & Technology Co., LTD reported this vulnerability to Mitsubishi Electric.

4. MITIGATIONS To minimize the risk, Mitsubishi Electric recommends customers apply the following mitigations: Use a firewall or virtual private network (VPN), etc. to prevent unauthorized access when Internet access is required. Install anti-virus software on the PC that can access the product. Use within a LAN and block access from untrusted networks and hosts through firewalls. Restrict physical access to the affected product and the LAN to which the product is connected. CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet. 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.