ID:6736 - Exploit for Inconsistent interpretation of HTTP requests in HAProxy - CVE-2021-40346

Link to public exploit:

Vulnerability description

The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP/2 requests within the htx_add_header() and htx_add_trailer() functions when processing HTTP header name length encoding in the HTX representation. A remote attacker can send a specially crafted HTTP request to the server and smuggle HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

Remediation