ICS Advisory (ICSA-20-245-01)

Mitsubishi Electric Multiple Products

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  • CVSS v3 7.3
  • ATTENTION: Exploitable remotely/low skill level to exploit
  • Vendor: Mitsubishi Electric
  • Equipment: Multiple Products
  • Vulnerability: Predictable Exact Value from Previous Values


Successful exploitation of this vulnerability could be used to hijack TCP sessions and allow remote command execution.



  • QJ71MES96, all versions
  • QJ71WS96, all versions
  • Q06CCPU-V, all versions
  • Q24DHCCPU-V, all versions
  • Q24DHCCPU-VG, all versions
  • R12CCPU-V, all versions
  • RD55UP06-V, all versions
  • RD55UP12-V, all versions
  • RJ71GN11-T2, all versions
  • RJ71EN71, all versions
  • QJ71E71-100, all versions
  • LJ71E71-100, all versions
  • QJ71MT91, all versions
  • RD78Gn(n=4,8,16,32,64), all versions
  • RD78GHV, all versions
  • RD78GHW, all versions
  • NZ2GACP620-60, all versions
  • NZ2GACP620-300, all versions
  • NZ2FT-MT, all versions
  • NZ2FT-EIP, all versions
  • Q03UDECPU, the first 5 digits of serial number 22081 and prior
  • QnUDEHCPU(n=04/06/10/13/20/26/50/100), the first 5 digits of serial number 22081 and prior
  • QnUDVCPU(n=03/04/06/13/26), the first 5 digits of serial number 22031 and prior
  • QnUDPVCPU(n=04/06/13/2), the first 5 digits of serial number 22031 and prior
  • LnCPU(-P)(n=02/06/26), the first 5 digits of serial number 22051 and prior
  • L26CPU-(P)BT, the first 5 digits of serial number 22051 and prior
  • RnCPU(n=00/01/02), Version 18 and prior
  • RnCPU(n=04/08/16/32/120), Version 50 and prior
  • RnENCPU(n=04/08/16/32/120), Version 50 and prior
  • RnSFCPU (n=08/16/32/120), all versions
  • RnPCPU(n=08/16/32/120), all versions
  • RnPSFCPU(n=08/16/32/120), all versions
  • FX5U(C)-**M*/**
    •  Case1: Serial number 17X**** or later: Version 1.210 and prior
    •  Case2: Serial number 179**** and prior: Version 1.070 and prior
  • FX5UC-32M*/**-TS, Version 1.210 and prior
  • FX5UJ-**M*/**, Version 1.000
  • FX5-ENET, all versions
  • FX5-ENET/IP, all versions
  • FX3U-ENET-ADP, all versions
  • FX3GE-**M*/**, all versions
  • FX3U-ENET, all versions
  • FX3U-ENET-L, all versions
  • FX3U-ENET-P502, all versions
  • FX5-CCLGN-MS, all versions
  • IU1-1M20-D, all versions
  • LE7-40GU-L, all versions
  • GOT2000 Series GT21 Model, all versions
  • GS Series, all versions
  • GOT1000 Series GT14 Model, all versions
  • GT25-J71GN13-T2, all versions
  • FR-A800-E Series, all versions
  • FR-F800-E Series, all versions
  • FR-A8NCG, Production date August 2020 and prior
  • FR-E800-EPA Series, Production date July 2020 and prior
  • FR-E800-EPB Series, Production date July 2020 and prior
  • Conveyor Tracking Application APR-nTR3FH, APR-nTR6FH, APR-nTR12FH, APR-nTR20FH(n=1,2), all versions (Discontinued product)
  • MR-JE-C, all versions
  • MR-J4-TM, all versions



The affected products are vulnerable to impersonation of a legitimate device by a malicious actor, which may allow an attacker to remotely execute arbitrary commands.

CVE-2020-16226 has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).




Ta-Lun Yen of TXOne IoT/ICS Security Research Labs of Trend Micro, working with Trend Micro’s Zero Day Initiative, reported this vulnerability to CISA.


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

  • Use a firewall or VPN, etc. to prevent unauthorized access when Internet access is required.
  • Use within a LAN and ensure that they are not accessible from untrusted networks and hosts.
  • Install an antivirus software in your personal computer that can access the product.
  • RnCPU(n=00/01/02), Version 18 and prior: Update to Version 19 or later.
  • RnCPU(n=04/08/16/32/120), Version 50 and prior. Please update to Version 51 or later.
  • RnENCPU(n=04/08/16/32/120), Versions 50 and prior: Update to Version 51 or later.
  • FX5U(C)-**M*/**
    • Case1: Serial number 17X**** or later, Version 1.210 and prior: Update to Version 1.211 or later.
    • Case2: Serial number 179**** and prior, Version 1.070 and prior: Update to Version 1.071 or later.
  • FX5UC-32M*/**-TS, Version 1.210 and prior: Update to Version 1.211 or later.
  • FX5UJ-**M*/**, Version 1.000: Update to Version 1.001 or later.

Please contact Mitsubishi Electric for more 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 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 that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.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.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.

Contact Information

For any questions related to this report, please contact the CISA at:

Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  https://us-cert.cisa.gov/ics 
or incident reporting:  https://us-cert.cisa.gov/report

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