CVE-2021-39242

Published: Aug 17, 2021Modified: Jun 17, 2026

7.5

Vector

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

Exploitability: 3.9 / Impact: 3.6

Source: NVD

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.

Affected (6)

Products: Haproxy: Haproxy · Debian: Debian Linux · Fedoraproject: Fedora

1 product

1 product

1 product

Configuration A

3 vulnerable

Vulnerable Software	Affected Versions
Haproxy Haproxy	From 2.2.0 to 2.2.16
Haproxy Haproxy	From 2.3.0 to 2.3.13
Haproxy Haproxy	From 2.4.0 to 2.4.3

Configuration B

1 vulnerable

Vulnerable Software	Affected Versions
Debian Debian Linux	Version 11.0

Configuration C

2 vulnerable

Vulnerable Software	Affected Versions
Fedoraproject Fedora	Version 33
Fedoraproject Fedora	Version 34

Related CWEs

CWE-755

Improper Handling of Exceptional Conditions

The product does not handle or incorrectly handles an exceptional condition.

References (10)

https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1

Source: cve@mitre.org

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/

Source: cve@mitre.org

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/

Source: cve@mitre.org

https://www.debian.org/security/2021/dsa-4960

Source: cve@mitre.org

Third Party Advisory

https://www.mail-archive.com/haproxy%40formilux.org/msg41041.html

Source: cve@mitre.org

https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=b5d2b9e154d78e4075db163826c5e0f6d31b2ab1