Eikon Thomson Reuters 4.0.42144 File Permissions Vulnerability

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              title: Extensive file permissions on service executable
            product: Eikon Thomson Reuters
 vulnerable version: 4.0.42144
      fixed version: -
         CVE number: CVE-2019-10679
             impact: High
           homepage: eikon.thomsonreuters.com
              found: 2019-03-18
                 by: Khalil Bijjou (Office CH)
                     SEC Consult Vulnerability Lab

                     An integrated part of SEC Consult
                     Europe | Asia | North America

                     https://www.sec-consult.com

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Vendor description:
-------------------
"Eikon is the financial analysis desktop and mobile solution that connects you t
relevant, trusted content, Reuters news, markets, liquidity pools, and colleagues."

Source: https://www.refinitiv.com/en/products/spot-matching-forwards-matching


Business recommendation:
------------------------
As long as the vendor did not release a patch for this vulnerability, we recommend
moving Eikon Thomson Reuters to a separate system outside the domain to which users
can connect to. Furthermore, we recommend to closely monitor any activities related
to Eikon Thomson Reuters.


Vulnerability overview/description:
-----------------------------------
The current file permissions of the directory
"C:\Program Files (x86)\Thomson Reuters)\Eikon" allow users of the group
Authenticated Users to modify files in the folder. As these files are executed
by the service that runs with SYSTEM privileges, it is possible to escalate
privileges and create a new user with administrator privileges.


Proof of concept:
-----------------
The service's executable file is writeable by members of the Authenticated
Users group. A user can create a malicious file that for example creates a
new user and adds him to the Administrators group and replace the service's
executable file with it.

As the service runs in the SYSTEM users context, the malicious file will be
executed the next time the service is started. As the SYSTEM user has the
highest privileges, the mentioned actions are successfully performed and a new
user will be created and added to the administrators group.

Creating a new user represents only an example. Other critical actions can be
performed instead.


Vulnerable / tested versions:
-----------------------------
The following version has been tested which was the latest version available at
the time of discovery:
* 4.0.42144


Vendor contact timeline:
------------------------
2019-04-09: Contacting vendor through the contact form in the homepage.
            Service request number is 07521820.
2019-04-09: Received reply that they will supply a security contact.
2019-04-16: Sent reminder as no security contact has been supplied yet.
2019-04-23: Sent reminder #2.
2019-04-23: Vendor replied: "Thank you for your reminder, the release
            date has been duly noted. As previously mentioned, I have
            transferred your query to our security specialists already,
            they will reach out to you if they deem it necessary."
2020-08-26: Release of security advisory.


Solution:
---------
As the vendor has not responded to any of our further requests, we are
currently unaware, whether a fix has been published or not. In any case,
we recommend to run the application on a separate server to which users
have to connect (e.g. via RDP).


Workaround:
-----------
We recommend enabling write permissions to administrative users only
and to adhere to updating best practices.