A high-severity vulnerability (CVE-2024-5102) has been discovered in Avast Antivirus for Windows, potentially allowing attackers to gain elevated privileges and wreak havoc on users’ systems. This flaw, present in versions prior to 24.2, resides within the “Repair” feature, a tool designed to fix issues with the antivirus software itself.
The vulnerability stems from how the repair function handles symbolic links (symlinks). By manipulating these links, an attacker can trick the repair function into deleting arbitrary files or even executing code with the highest system privileges (NT AUTHORITY\SYSTEM). This could allow them to delete critical system files, install malware, or steal sensitive data.
Exploiting this vulnerability involves a race condition, where the attacker must win a race against the system to recreate specific files and redirect Windows to a malicious file. While this adds a layer of complexity to the attack, successful exploitation could have devastating consequences.
“This can provide a low-privileged user an Elevation of Privilege to win a race-condition which will re-create the system files and make Windows callback to a specially-crafted file which could be used to launch a privileged shell instance,” reads the Norton security advisories.
Avast has addressed this vulnerability in version 24.2 and later of their antivirus software. Users are strongly encouraged to update their software immediately to protect themselves from potential attacks.
This vulnerability was discovered by security researcher Naor Hodorov.
Users of Avast Antivirus should prioritize updating to the latest version to mitigate the risk of exploitation. Ignoring this vulnerability could leave systems vulnerable to serious attacks, potentially leading to data loss, system instability, and malware infections.