Mitsubishi Electric CNC Series (Update E)

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:

• M800VW (BND-2051W000-**): Versions A8 and prior
• M800VS (BND-2052W000-**): Versions A8 and prior
• M80V (BND-2053W000-**): Versions A8 and prior
• M80VW (BND-2054W000-**): Versions A8 and prior
• M800W (BND-2005W000-**): Versions FB and prior
• M800S (BND-2006W000-**): Versions FB and prior
• M80 (BND-2007W000-**): Versions FB and prior
• M80W (BND-2008W000-**): Versions FB and prior
• E80 (BND-2009W000-**): Versions FB and prior
• C80 (BND-2036W000-**): Versions BF and prior
• M750VW (BND-1015W002-**): Versions LF and prior
• M730VW/M720VW (BND-1015W000-**): Versions LF and prior
• M750VS (BND-1012W002-**): Versions LF and prior
• M730VS/M720VS (BND-1012W000-**): Versions LF and prior
• M70V (BND-1018W000-**): Versions LF and prior
• E70 (BND-1022W000-**): Versions LF and prior
• Remote Service Gateway Unit (BND-2041W001-**): Versions AD and prior
• 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 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

Mitsubishi Electric has provided a fix for the following products:

• M800VW (BND-2051W000-**): Versions A9 or later
• M800VS (BND-2052W000-**): Versions A9 or later
• M80V (BND-2053W000-**): Versions A9 or later
• M80VW (BND-2054W000-**): Versions A9 or later
• M800W (BND-2005W000-**): Versions FC or later
• M800S (BND-2006W000-**): Versions FC or later
• M80 (BND-2007W000-**): Versions FC or later
• M80W (BND-2008W000-**): Versions FC or later
• E80 (BND-2009W000-**): Versions FC or later
• C80 (BND-2036W000-**): Versions BG or later
• M750VW (BND-1015W002-**): Versions LG or later
• M730VW/M720VW (BND-1015W000-**): Versions LG or later
• M750VS (BND-1012W002-**): Versions Versions LG or later
• M730VS/M720VS (BND-1012W000-**): Versions LG or later
• M70V (BND-1018W000-**): Versions LG or later
• E70 (BND-1022W000-**): Versions LG or later
• Remote Service Gateway Unit (BND-2041W001-**): Versions AE or later

For specific update instructions and additional details refer to Mitsubishi Electric advisory 2023-007.

For users that are unable to update their systems immediately, Mitsubishi Electric recommends applying the mitigations below to minimize the risk:

• 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, such as:

• Minimize network exposure for all control system devices and/or systems, ensuring 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 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 exploits specifically target this vulnerability.

5. UPDATE HISTORY

• July 27, 2023: Initial Publication
• August 3, 2023: Update A - Additional products were added under M700V/M70V/E70 Series
• October 31, 2023: Update B - Corrected Affected versions of M800/M80/E80 Series products, Added fixes for M800/M80/E80 Series products and additional Mitigation information in the Mitigation section.
• November 21, 2023: Update C - Updated affected versions in Affected Products section. Added fixed versions for M800/M80V Series and M700V/M70V/E70 Series products in Mitigation section.
• December 5, 2023: Update D - Added countermeasures to Remote Service Gateway Unit.
• January 30, 2024: Update E - Added C80 and versions to Affected Products and Mitigations sections.