CVE-2021-40438

Publication date 16 September 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
apache2	22.04 LTS jammy	Fixed 2.4.48-3.1ubuntu2
	21.10 impish	Fixed 2.4.48-3.1ubuntu2
	21.04 hirsute	Fixed 2.4.46-4ubuntu1.3
	20.04 LTS focal	Fixed 2.4.41-4ubuntu3.6
	18.04 LTS bionic	Fixed 2.4.29-1ubuntu4.18
	16.04 LTS xenial	Fixed 2.4.18-2ubuntu3.17+esm3
	14.04 LTS trusty	Not affected

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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
apache2	Upstream: d4901cb

Severity score breakdown

Parameter	Value
Base score	9.0 · Critical
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Changed
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H