Advisory Details

July 29th, 2025

Avast Cleanup Premium TuneupSvc Link Following Local Privilege Escalation Vulnerability

ZDI-25-696
ZDI-CAN-25549

CVE ID CVE-2024-13961
CVSS SCORE 7.8, AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS Avast
AFFECTED PRODUCTS Cleanup Premium
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the Avast Cleanup Service. By creating a symbolic link, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM.

ADDITIONAL DETAILS

Fixed in Avast Cleanup 24.3-SU1 - 24.3.17165.19178


DISCLOSURE TIMELINE
  • 2024-11-05 - Vulnerability reported to vendor
  • 2025-07-29 - Coordinated public release of advisory
  • 2025-07-29 - Advisory Updated
CREDIT Vladislav Berghici
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