CVE-2021-45339 json
Privilege escalation vulnerability in Avast Antivirus prior to 20.4 allows a local user to gain elevated privileges by "hollowing" trusted…
published 2021-12-27 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-32112
- cvss
- 7.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 25%
- public exploits
- 0
- none known
Summary
Privilege escalation vulnerability in Avast Antivirus prior to 20.4 allows a local user to gain elevated privileges by "hollowing" trusted process which could lead to the bypassing of Avast self-defense.
Patch / fix
- avast antivirus 20.4
Exploit prediction
0.33% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/the-deniss/Vulnerability-Disclosures/tree/main/CVE-2021-AVST0 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.2 | AV:L/AC:L/Au:N/C:C/I:C/A:C |
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
-
github.com
/the-deniss/Vulnerability-Disclosures/tree/main/CVE-2021-AVST0
exploit, third-party-advisory
-
avast.com
/hacker-hall-of-fame/en/researcher-david-eade-reports-antitrack-bug-to-avast-0
vendor-advisory
Sources
- CVE List CVE-2021-45339
- NVD CVE-2021-45339
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