CVE-2021-45338: Avast Antivirus

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Multiple privilege escalation vulnerabilities in Avast Antivirus prior to 20.4 allow a local user to gain elevated privileges by calling unnecessarily powerful internal methods of the main antivirus service which could lead to the (1) arbitrary file delete, (2) write and (3) reset security.

Affected products

• Avast Antivirus: before 20.4 (fixed in 20.4)

Published 2021-12-27. Last modified 2026-06-17.