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.