CVE-2019-10191

Publication date 10 July 2019

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote attackers to downgrade DNSSEC-secure domains to DNSSEC-insecure state, opening possibility of domain hijack using attacks against insecure DNS protocol.

Read the notes from the security team

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
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Fixed 3.2.1-3ubuntu2.2
	19.10 eoan	Ignored end of life
	19.04 disco	Ignored end of life
	18.10 cosmic	Ignored end of life
	18.04 LTS bionic	Vulnerable
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Not in release

Notes

alexmurray

According to the upstream advisory all version <= 4.0.0 are affected

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: https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/839/commits

Severity score breakdown

Parameter	Value
Base score	6.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	Low
Availability impact	Low
Vector	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L