Avast antivirus use of stack memory after free when scanning a malformed PE file

Use of stack memory after free vulnerability in Avast Antivirus when scanning a malformed Windows PE file may allow Denial-of-Service of the antivirus process.

This issue affects Avast Antivirus, AVG Antivirus, Norton Antivirus, Avast One, and Avast Business Antivirus on Windows, macOS, and Linux for virus definition builds before VPS 25022500.

The affected scanning logic is delivered through a shared Gen Digital virus definition update stream. The same stream feeds the consumer antivirus products listed in this advisory and other Gen Digital products that embed the same engine. Mitigation flows through this update channel; installations at or above the listed build are not vulnerable regardless of which product consumes the stream.