Mitsubishi Electric GOT2000

1. EXECUTIVE SUMMARY

• CVSS v3 5.3
• ATTENTION: Exploitable remotely 
• Vendor: Mitsubishi Electric 
• Equipment: GOT2000 Series 
• Vulnerability: Improper Input Validation 

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to cause a denial-of-service condition by sending a specially crafted command. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Mitsubishi Electric GOT2000 Series products are affected: 

• GT27 Model: FTP server versions 01.39.000 and prior 
• GT25 Model: FTP server versions 01.39.000 and prior 
• GT23 Model: FTP server versions 01.39.000 and prior 

3.2 VULNERABILITY OVERVIEW

3.2.1 IMPROPER INPUT VALIDATION CWE-20 

The affected GOT2000 Series devices with FTP server versions 01.39.000 and prior are vulnerable to improper input validation, which could allow an attacker to cause a denial-of-service condition by sending a specially crafted command. 

CVE-2022-40266 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H). 

3.3 BACKGROUND

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

3.4 RESEARCHER

Mitsubishi Electric reported this vulnerability to CISA. 

4. MITIGATIONS

Mitsubishi Electric recommends users update to the latest software versions: 

• GT27 Model: Update to FTP server versions 01.47.000 or later 
• GT25 Model: Update to FTP server versions 01.47.000 or later  
• GT23 Model: Update to FTP server versions 01.47.000 or later 

The following steps were provided by Mitsubishi Electric to assist users in applying the update: 

1. Download the fixed version of GT Designer3 Version1 (GOT2000) and install on a compatible device. 

• Users should contact Mitsubishi Electric for GT Designer3 Version1 (GOT2000). 

2. Start the GT Designer3 Version1 (GOT2000) and open the project data used in affected products. 

3. Select [Write to GOT] from [Communication] menu to write the required package data to the GOT.

• Users can refer to the GT Designer3 Version1 (GOT2000) Screen Design Manual (SH-081220ENG). “COMMUNICATING WITH GOT” 

4. After writing the required package data to the GOT, refer to the <How to check the versions in use> and ensure the software has been updated to the fixed versions. 

Mitsubishi Electric also recommends users to take steps to mitigate risk of vulnerability exploitation:  

• When internet access is required, use a virtual private network (VPN) or other secure means to prevent unauthorized access. 
• Only use products inside a local area network (LAN).  
• Block access from untrusted networks and hosts. 
• Install antivirus software on the host where products are installed.  
• Set strong passwords to prevent unauthorized login. 
• Use the IP filter function*1 to control IP address access to the host machine with installed software 
  • *1: GT Designer3 (GOT2000) Screen Design Manual (SH-081220ENG). “5.4.3 Setting the IP filter” 

Users should refer to Mitsubishi Electric’s security advisory for further information. 

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.
• Locate control system networks and remote devices behind firewalls and isolate them from the business network.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

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 recommended 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 on cisa.gov/ics in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

CISA also recommends users take the following measures to protect themselves from social engineering attacks: 

• Do not click web links or open attachments in unsolicited email messages. 
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. 
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. 

No known public exploits specifically target this vulnerability. This vulnerability has a high attack complexity.