CVE-2021-45339

HIGHNVD 7.87.8—

7.8

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.

CVSS v3: 7.8
EG Score: 7.8(medium)
EPSS: 10.4%
KEV: Not listed

Published

December 27, 2021

Last Modified

November 21, 2024

References (4)

cve@mitrehttps://github.com/the-deniss/Vulnerability-Disclosures/tree/main/CVE-2021-AVST0
cve@mitrehttps://www.avast.com/hacker-hall-of-fame/en/researcher-david-eade-reports-antitrack-bug-to-avast-0
af854a3a-2127-422b-91ae-364da2661108https://github.com/the-deniss/Vulnerability-Disclosures/tree/main/CVE-2021-AVST0
af854a3a-2127-422b-91ae-364da2661108https://www.avast.com/hacker-hall-of-fame/en/researcher-david-eade-reports-antitrack-bug-to-avast-0

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-06 13:46 UTCepss_batch
2026-06-06 13:46 UTCepss_batch
2026-06-05 22:45 UTCepss_batch
2026-06-05 06:09 UTCepss_batch
2026-06-05 06:09 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch

Frequently asked(5)

What is CVE-2021-45339?

CVE-2021-45339 is a high vulnerability published on December 27, 2021. 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.

When was CVE-2021-45339 disclosed?

CVE-2021-45339 was first published in the National Vulnerability Database on December 27, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-45339 actively exploited?

CVE-2021-45339 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 10.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-45339?

CVE-2021-45339 has a CVSS v3 base score of 7.8 (NVD).

How do I remediate CVE-2021-45339?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-45339, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-45339

Explore →

Is Your Infrastructure Affected by CVE-2021-45339?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2021-45339

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(2)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-45339?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (4)

Frequently asked(5)

Related CVEs(same CWE)