Advisory Details

This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the AvastSvc.exe module. By creating a directory junction, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

Fixed in Avast v20.10

• 2020-11-18 - Vulnerability reported to vendor
• 2021-02-24 - Coordinated public release of advisory