Multiple Vulnerabilities in Distributed Data Systems WebHMI Could Allow for Arbitrary Code Execution

DESCRIPTION:
Multiple vulnerabilities have been discovered in Distributed Data
Systems WebHMI, the most severe of which could allow for arbitrary code
execution. Distributed Data Systems WebHMI is a SCADA system with a
built-in web server that allows you to monitor and control any
automation system on the local network and via the Internet from your
computer and mobile devices. Successful exploitation of the most severe
of these vulnerabilities could allow an administrator account login
without password authentication and remote code execution with root
privileges. Depending on the privileges associated with this system, an
attacker could then install programs; view, change, or delete data; or
create new accounts with full user rights. If this system has been
configured to have fewer user rights, exploitation of these
vulnerabilities could have less impact than if it was configured with
administrative rights.

IMPACT:
Multiple vulnerabilities has been discovered in Distributed Data Systems
WebHMI, the most severe of which could allow for arbitrary code
execution. The vulnerabilities affect an unknown code block of the
component Portal and are as follows:

* An Improper Authentication vulnerability exists due to a separate
weakness primary to the authentication error. A remote attacker can
bypass authentication process and gain unauthorized access to the
application. (CVE-2021-43931)
* An Arbitrary File Upload vulnerability exists due to insufficient
validation of file during file upload. A remote attacker can upload a
malicious file and execute it on the server. (CVE-2021-43936)

Successful exploitation of the most severe of these vulnerabilities
could allow an administrator account login without password
authentication and arbitrary code execution with root privileges.
Depending on the privileges associated with this system, an attacker
could then install programs; view, change, or delete data; or create new
accounts with full user rights. If this application has been configured
to have fewer user rights on the system, exploitation of these
vulnerabilities could have less impact than if it was configured with
administrative rights.

SYSTEM AFFECTED:
* Distributed Data Systems WebHMI versions prior 4.1

RECOMMENDATIONS:
We recommend the following actions be taken:

* 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.
* Run all software as a non-privileged user (one without administrative
privileges) to diminish the effects of a successful attack.
* Apply the Principle of Least Privilege to all systems and services.

REFERENCES:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43931
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43936
https://us-cert.cisa.gov/ics/advisories/icsa-21-336-03

Published: 13 January 2022, 16:39:03 BST