Is CVE-2021-45339 in the CISA KEV catalog?

No. CVE-2021-45339 is not currently on the CISA Known Exploited Vulnerabilities list.

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

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

What is the EPSS score for CVE-2021-45339?

CVE-2021-45339 has an EPSS score of 0.32% (23th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-45339?

Upgrade antivirus to 20.4 or later.

CVE & CISA-KEV Catalog

CVE-2021-45339

HIGH

7.8

CVSS v3

NVD

Description

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.

CWE-863Incorrect Authorization

How to fix

Remediation Available

antivirusNVD

Affected:< 20.4Fixed in:20.4CVE-2021-45339derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.32%probability of exploitation in 30 days

23rdpercentile

Low risk: more likely to be exploited than 23% of all known CVEs.

References

Exploit1

github.com

Vendor Advisory1

avast.com

Related Vulnerabilities

Other CWE-863 (Incorrect Authorization) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-22518	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-38035	Critical	9.8	100%	KEV + Ransom	-
CVE-2022-46169	Critical	9.8	100%	KEV	Fix
CVE-2025-29927	Critical	9.1	100%	-	Fix
CVE-2024-38856	Critical	9.8	99%	KEV	Fix
CVE-2020-36289	Medium	5.3	99%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.