This blog contains information about the Dell drivers vulnerabilities. As soon as we have an update, we’ll add it to this post. More information about possible risks and details can be found at the bottom of this blog.
Update May 5, 2021
18:00 | A vulnerability has been found in one of Dell’s kernel drivers labeled CVE-2021-21551. This vulnerability affects hundreds of models, which can be found in the tables on the page of the patch. The error concerns an incorrectly implemented access control, which can cause “privilege escalation”, “denial of service” or “information disclosure”.
Attention: Patching only solves part of the problem, as the problem can be re-occur after a backup has been put back. In addition to patching, it is therefor recommended to set the monitoring for the reappearance of the file ‘dbutil_2_3.sys’.
Reason and background of this blog
This blog contains information about vulnerabilities, the possible risk and advice on how to prevent or limit damage. Below are the possible risks, details and background information.
There is a patch from Dell that only partially fixes the problem, however. The problem or danger is mainly that if someone makes (or has) a backup, the bug will be available again through a downgrade attack. After the patch (mainly in temporary directories such as TEMP), the file dbutil_2_3.sys can be regarded as an Indicator of Compromise.