A significant vulnerability, designated as CVE-2025-3500, has been identified in Avast Free Antivirus, allowing attackers to gain elevated system privileges and execute malicious code at the kernel level. The vulnerability has a high CVSS score of 8.8 and was publicly disclosed on April 24, 2025, shortly after a patch was implemented. It originates from inadequate validation of user-supplied data in the aswbidsdriver kernel driver, leading to an integer overflow prior to buffer allocation. Attackers must first execute low-privileged code on the target system to exploit this vulnerability. The flaw affects multiple versions of Avast Free Antivirus, specifically versions ranging from 20.1.2397 to 2016.11.1.2262. A fix was released in version 25.3.9983.922, and users are urged to update their software promptly. Security experts recommend enabling automatic updates and using standard user accounts for daily activities to mitigate risks.