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TI-2025-03672 Aliases CVE-2025-4134GHSA-cj5g-8945-q3rg

Lack of file validation in Avast Business Antivirus for Linux allows writing untrusted update files

Priority LOW 33CWE-552Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-552.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00219 12th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
AvastAvast Business Antivirus4.5.1—No fix listedCNA
  • Avast Business Antivirus VendorAvast Affected 4.5.1 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-4134
  2. 2026-10-03 Alias added: GHSA-cj5g-8945-q3rg

References

Other 1

  • TI-2025-43447 AVAST Antivirus 25.11 Unquoted Service Path Privilege Escalation CVSS 4.0HIGH 8.5
  • TI-2020-19172 AVAST SecureLine 5.5.522.0 - 'SecureLine' Unquoted Service Path CVSS 4.0HIGH 8.5
  • TI-2010-02987 Untrusted search path vulnerability in avast! Free Antivirus version 5.0.594 and earlier… CVSS 2.0HIGH 9.3
  • TI-2007-02752 Heap-based buffer overflow in the CAB unpacker in avast! Anti-Virus Managed Client before… CVSS 2.0HIGH 9.3
  • TI-2020-14724 An issue was discovered in retdec v3.3. CVSS 3.1CRITICAL 9.8
  • TI-2020-08753 An issue was discovered in Avast Antivirus before 20. CVSS 3.1CRITICAL 9.8
See all 83 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences