CVE-2021-39242

HIGH

Haproxy < 2.2.16 - Improper Exception Handling

Title source: rule

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.

References (5)

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

[Third Party Advisory] https://www.debian.org/security/2021/dsa-4960

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

[Mailing List, Third Party Advisory] https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ALECUZDIMT5FYGP6V6PVSI4BKVZTZWN/

[Mailing List, Third Party Advisory] https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPNY4WZIQUAUOCLIMUPC37AQWNXTWIQM/

Scores

CVSS v3 7.5

EPSS 0.0047

EPSS Percentile 64.1%

Attack Vector NETWORK

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

Classification

CWE

CWE-755

Status published

Affected Products (4)

haproxy/haproxy < 2.2.16

debian/debian_linux

fedoraproject/fedora

Timeline

Published Aug 17, 2021

Tracked Since Feb 18, 2026