High severity · published May 28, 2025
CVE-2025-4134
Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files
7.3
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AB
Avast Business Antivirus · Avast
4.5.1 · source: vendor