Vulnerability · Published Jun 10, 2024 · Assigned by NLOK
CVE-2024-5102Elevation of Privelage via symlinked file in Avast Antivirus
High 7.3
In plain English
A high-severity security flaw in Antivirus from Avast. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).
Official description
A sym-linked file accessed via the repair function in Avast Antivirus <24.2 on Windows may allow user to elevate privilege to delete arbitrary files or run processes as NT AUTHORITY\SYSTEM. The vulnerability exists within the "Repair" (settings -> troubleshooting -> repair) feature, which attempts to delete a file in the current user's AppData directory as NT AUTHORITY\SYSTEM. A low-privileged user can make a pseudo-symlink and a junction folder and point to a file on the system. 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. This issue affects Avast Antivirus prior to 24.2.
Affected products (as reported)
Weakness: CWE-1284 · Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H