CVE-2022-40188

Publication date 23 September 2022

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU consumption) because of algorithmic complexity. During an attack, an authoritative server must return large NS sets or address sets.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
knot-resolver	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Fixed 5.5.1-5ubuntu0.22.10.1
	22.04 LTS jammy	Fixed 5.4.4-1ubuntu0.1~esm1
	20.04 LTS focal	Fixed 3.2.1-3ubuntu2.1
	18.04 LTS bionic	Fixed 2.1.1-1ubuntu0.1~esm2
	16.04 LTS xenial	Fixed 1.0.0~beta3-1ubuntu0.1~esm1
	14.04 LTS trusty	Ignored end of standard support

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
knot-resolver	Upstream: f6577a2

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-6225-1
Knot Resolver vulnerability
13 July 2023