Link Following Local Privilege Escalation Vulnerability in TuneupSvc in Avast Cleanup Premium Version 24.2.16593.17810 on Windows 10 Pro x64 allows local attackers to escalate privileges and execute arbitrary code in the context of SYSTEM via creating a symbolic link and leveraging a TOCTTOU (time-of-check to time-of-use) attack.
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.