CVE-2025-4134 json
Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files
published 2025-05-28 17 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-16299
- cvss
- 7.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 17 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
Affected products
- Avast Avast Business Antivirus
Classification
- Weakness
-
- CWE-552 Files or Directories Accessible to External Parties
References
Sources
- CVE List CVE-2025-4134
- NVD CVE-2025-4134
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.