Check Point Advisories

Squid Proxy ESI Response Processing Denial of Service (CVE-2016-4555)

Vulnerability
Protection

Check Point Reference:	CPAI-2016-0971
Date Published:	1 Nov 2016
Severity:	Medium
Last Updated:	Tuesday 06 December, 2016
Source:	Squid Project SQUID-2016:9
Industry Reference:	CVE-2016-4555
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Squid Project Squid 3.x prior to 3.5.18 Squid Project Squid 4.x prior to 4.0.10
Vulnerability Description	A denial of service vulnerability has been reported in the Edge Side Includes (ESI) component of the Squid proxy. The vulnerability is due to incorrect pointer handling when processing ESI responses. A remote attacker could exploit this vulnerability by sending crafted ESI response data to the target system.

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 Proxy ESI Response Processing 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 Proxy ESI Response Processing Denial of Service