CVE-2021-27241: Avast Premium Security

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security 20.8.2429 (Build 20.8.5653.561). 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. Was ZDI-CAN-12082.

Affected products

• Avast Premium Security: version 20.8.2429 only

Published 2021-03-29. Last modified 2026-06-17.