Check Point Advisories

Squid HTTP Host Header Port Handling Denial of Service (CVE-2013-4123)

Vulnerability
Protection

Check Point Reference:	CPAI-2013-2491
Date Published:	17 Jul 2013
Severity:	Critical
Last Updated:	Wednesday 02 October, 2013
Source:
Industry Reference:	CVE-2013-4123
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	A denial-of-service vulnerability exists in Squid proxy. The vulnerability is due to incorrect validation of port values in the HTTP Host header. A remote attacker could exploit this vulnerability by sending a specially crafted request to the vulnerable server. A successful attack attempt would result in the termination of Squid proxy server creating a denial-of-service condition.

Protection Overview

This protection will detect and block attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R80 / R77 / R75

In the IPS tab, click Protections and find the Squid HTTP Host Header Port Handling Denial of Service protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Proxy Server Enforcement Violation.
Attack Information: Squid HTTP Host Header Port Handling denial of service