HTTP Host Header Vulnerability in HAProxy by HAProxy Technologies
CVE-2021-39242

7.5HIGH

Key Information:

Vendor: Haproxy
Status: Haproxy
Vendor: CVE Published:; 17 August 2021

What is CVE-2021-39242?

An issue in HAProxy versions prior to 2.2.16, 2.3.13, and 2.4.3 arises from how the software processes HTTP Host headers. Attackers can exploit this flaw by sending specially crafted requests that manipulate the Host header, leading to potential security risks through improper handling of the request's authority component. This may allow unauthorized access to resources or unintended behavior, necessitating immediate updates to affected versions.