-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2021.1389
             Advisory (icsa-21-112-02) Mitsubishi Electric GOT
                               23 April 2021

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Mitsubishi Electric GOT SIMPLE series products
                   Mitsubishi Electric GOT2000 series products
Operating System:  Network Appliance
Impact/Access:     Unauthorised Access -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2021-20590  

Original Bulletin: 
   https://us-cert.cisa.gov/ics/advisories/icsa-21-112-02

- --------------------------BEGIN INCLUDED TEXT--------------------

ICS Advisory (ICSA-21-112-02)

Mitsubishi Electric GOT

Original release date: April 22, 2021

Legal Notice

All information products included in https://us-cert.cisa.gov/ics are provided
"as is" for informational purposes only. The Department of Homeland Security
(DHS) does not provide any warranties of any kind regarding any information
contained within. DHS does not endorse any commercial product or service,
referenced in this product or otherwise. Further dissemination of this product
is governed by the Traffic Light Protocol (TLP) marking in the header. For more
information about TLP, see https://us-cert.cisa.gov/tlp/ .



1. EXECUTIVE SUMMARY

  o CVSS v3 5.9
  o ATTENTION: Exploitable remotely
  o Vendor: Mitsubishi Electric
  o Equipment: GOT
  o Vulnerability: Improper Authentication

2. RISK EVALUATION

Successful exploitation of this vulnerability may allow an attacker to gain
unauthorized access.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Mitsubishi Electric reports the vulnerability affects the VNC function of the
following devices:

  o GOT2000 series
       GT27 model: All versions
       GT25 model: All versions
       GT21 model: All versions
           GT2107-WTBD: All versions
           GT2107-WTSD: All versions
  o GOT SIMPLE series
       GS21 model
           GS2110-WTBD-N: All versions
           GS2107-WTBD-N: All versions

3.2 VULNERABILITY OVERVIEW

3.2.1 IMPROPER AUTHENTICATION CWE-287

A password authentication bypass vulnerability exists in the VNC function of
the GOT2000 series and the GOT SIMPLE series due to improper authentication.

CVE-2021-20590 has been assigned to this vulnerability. A CVSS v3 base score of
5.9 has been calculated; the CVSS vector string is ( AV:N/AC:H/PR:N/UI:N/S:U/
C:N/I:H/A:N ).

3.3 BACKGROUND

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

3.4 RESEARCHER

Mitsubishi Electric reported this vulnerability to CISA.

4. MITIGATIONS

Mitsubishi Electric instructs users to restrict access to the product only from
trusted networks and hosts until they complete additional mitigations.

Please refer to the Mitsubishi Electric website for details.

CISA recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability. Specifically, users should:

  o Minimize network exposure for all control system devices and/or systems,
    and ensure that they are not accessible from the Internet .
  o Locate control system networks and remote devices behind firewalls, and
    isolate them from the business network.
  o 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. This
vulnerability has high attack complexity.

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

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

CISA continuously strives to improve its products and services. You can help by
choosing one of the links below to provide feedback about this product.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        https://www.auscert.org.au/bulletins/

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=U+aY
-----END PGP SIGNATURE-----