CVE-2021-39242

Publication date 17 August 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
haproxy	22.04 LTS jammy	Fixed 2.2.9-2ubuntu1
	21.10 impish	Fixed 2.2.9-2ubuntu1
	21.04 hirsute	Fixed 2.2.9-1ubuntu0.1
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release

Patch details

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

Package	Patch details
haproxy	Upstream: https://git.haproxy.org/?p=haproxy.git;a=commit;h=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	High
Availability impact	None

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

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