Is CVE-2021-3672 in the CISA KEV catalog?

No. CVE-2021-3672 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-3672?

CVE-2021-3672 has a CVSS v3 base score of 5.6 (MEDIUM).

What is the EPSS score for CVE-2021-3672?

CVE-2021-3672 has an EPSS score of 2.62% (84th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-3672?

Upgrade c-ares on debian 11 to 1.17.1-1+deb11u1 or later. Fixes are available for 5 affected products.

CVE & CISA-KEV Catalog

CVE-2021-3672

MEDIUMEPSS 84th pctl

5.6

CVSS v3

NVD

Description

A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability.

CWE-79Cross-Site Scripting (XSS)

How to fix

Remediation Available

c-aresDebian

Fixed in:1.17.1-1+deb11u1CVE-2021-3672

Fixed in:1.17.1-1.1CVE-2021-3672

c-aresUbuntu

Fixed in:1.10.0-3ubuntu0.2+esm1USN-5034-2

Fixed in:1.14.0-1ubuntu0.1USN-5034-1

Fixed in:1.15.0-1ubuntu0.1USN-5034-1

libc-ares2Ubuntu

Fixed in:1.10.0-3ubuntu0.2+esm1USN-5034-2

Fixed in:1.14.0-1ubuntu0.1USN-5034-1

Fixed in:1.15.0-1ubuntu0.1USN-5034-1

Node.jsWindows application

Affected:14.15.0 14.17.5Fixed in:14.17.5Node.js Foundation

Affected:16.0.0 16.6.2Fixed in:16.6.2Node.js Foundation

Affected:12.13.0 12.22.5Fixed in:12.22.5Node.js Foundation

Node.js (LTS)Windows application

Affected:16.0.0 16.6.2Fixed in:16.6.2Node.js Foundation

Affected:14.15.0 14.17.5Fixed in:14.17.5Node.js Foundation

Affected:12.13.0 12.22.5Fixed in:12.22.5Node.js Foundation

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 VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityLow

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

Exploit Intelligence

2.62%probability of exploitation in 30 days

84thpercentile

Elevated risk: more likely to be exploited than 84% of all known CVEs.

References

Patch2

Third-Party Advisory2

Other references1

security.gentoo.org

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-11022	Medium	6.9	99%	-	Fix
CVE-2019-3929	Critical	9.8	99%	KEV	Fix
CVE-2020-9496	Medium	6.1	99%	-	-
CVE-2023-28341	Medium	6.1	99%	-	Fix
CVE-2018-12998	Medium	6.1	98%	-	-
CVE-2025-4123	High	7.6	98%	-	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.