Vulnerabilities in Avast Antivirus, AVG Antivirus, and Avira Antivirus could allow an attacker to load a malicious DLL file in an effort to bypass defenses and escalate privileges
Tracked as CVE-2019-17093 and impacting all versions of Avast Antivirus and AVG Antivirus.The first security flaw could be abused to achieve what SafeBreach describes as self-defense bypass, defense evasion, persistence and privilege escalation. Exploitation of the bug requires administrative privileges, but could lead to loading a malicious DLL into multiple processes that run as NT AUTHORITY\SYSTEM.
The issue was found to impact all editions of Avast Antivirus and AVG Antivirus below version 19.8. A patch was released on September 26.
The researchers found a similar issue in Avira Antivirus 2019 and explain that it too could lead to “defense evasion, persistence and privilege escalation by loading an arbitrary unsigned DLL into multiple signed processes that run as NT AUTHORITY\SYSTEM.”
The researchers reported the vulnerability to Avira on July 22, and the vendor informed them on September 18 that the issue was addressed. MITRE issued CVE-2019-17449 for the vulnerability on October 10.