CVE-2025-4134 Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files
Local attackers can tamper with update files due to lack of validation, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-4134?
CVE-2025-4134 is a high-severity vulnerability in Avast Business Antivirus, published on 28 May 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Lack of file validation in do_update_vps in Avast Business Antivirus for Linux 4.5 on Linux allows local user to spoof or tamper with the update file via an unverified file write.
Weakness: CWE-552
Which versions are affected by CVE-2025-4134?
How do I fix CVE-2025-4134?
No fix has been published for CVE-2025-4134 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-4134 being exploited?
There is no known exploitation of CVE-2025-4134 in the wild and no public exploit code.
Sources
Also known as GHSA-cj5g-8945-q3rg.