Mitsubishi Electric GOT products

1. EXECUTIVE SUMMARY

• CVSS v3 7.5
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Mitsubishi Electric
• Equipment: GOT2000 series, GOT SIMPLE series, GT SoftGOT2000
• Vulnerability: Improper Input Validation

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow the system’s operations to be adversely affected.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Mitsubishi Electric human-machine interface (HMI) products are affected:

• GOT2000 series
  • GT27 model: All versions
  • GT25 model: All versions
  • GT23 model: All versions
  • GT21 model: All versions
• GOT SIMPLE series
  • GS21 model: All versions
• GT SoftGOT2000: All versions

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER INPUT VALIDATION CWE-20

The affected product is vulnerable to an information tampering vulnerability, which may allow an attacker to send a malicious packet to rewrite the device value and adversely affect the system’s operation.

CVE-2021-20601 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

3.3 BACKGROUND

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

3.4 RESEARCHER

Parul Sindhwad and Dr. Faruk Kazi of COE-CNDS Lab, VJTI, Mumbai, India, reported this vulnerability to Mitsubishi Electric.

4. MITIGATIONS

Mitsubishi Electric recommends users take measures such as installing a firewall to protect the GOT and system from unauthorized access from external equipment via the network.

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

• Use a firewall or virtual private network (VPN), etc. to prevent unauthorized access when Internet access is required.
• Use the products within a LAN and block access from untrusted networks and hosts.
• Install antivirus software on user computers with access to the product and the system.
• Use the IP filter function to restrict the accessible IP addresses.

For more information, please contact the local Mitsubishi Electric representative or refer to the Mitsubishi Electric support website.

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. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that 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 us-cert.cisa.gov. 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 us-cert.cisa.gov 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.

No known public exploits specifically target this vulnerability.