CVE-2025-4134
Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files
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.
- Record
CVE-2025-4134- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-552
- Updated
- 2026-11-02
EUVDEUVD-2025-16299
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.
- Record
EUVD-2025-16299- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cj5g-8945-q3rg
Lack of file validation in do_update_vps in Avast Business Antivirus for Linux 4.5 on Linux...
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.
- Record
GHSA-cj5g-8945-q3rg- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-552
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-4134- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-552
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-4134 is a high vulnerability (CVSS 7.3) in Avast Business Antivirus, published May 28, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. No source names a fixed version.