CVE-2021-3672

MEDIUM
5.6
CVSS Score
Published: November 23, 2021 at 12:00 AM UTC
Updated: June 17, 2026 at 04:05 AM UTC
18 products affected across 7 vendorsFedoraEnterprise LinuxEnterprise Linux Workstation

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Severity
MEDIUM5.6
Exploit prediction
EPSS 3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.0.0 ≤ v < 1.17.2
Affected range stops below 1.17.2, so it looks safe — our inference, not a vendor statement
12.0.0 ≤ v ≤ 12.12.012.13.0 ≤ v < 12.22.514.0.0 ≤ v ≤ 14.14.014.15.0 ≤ v < 14.17.516.0.0 ≤ v < 16.6.2
Affected range stops below 12.22.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 14.17.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.6.2, so it looks safe — our inference, not a vendor statement
v ≤ 1.17.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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