Check Point Advisories

OpenSSL DHE Client Key Exchange Denial of Service (CVE-2015-1787)

Vulnerability
Protection

Check Point Reference:	CPAI-2015-0491
Date Published:	13 May 2015
Severity:	High
Last Updated:	Sunday 03 December, 2017
Source:	OpenSSL
Industry Reference:	CVE-2015-1787
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	OpenSSL Project OpenSSL prior to 1.0.2a
Vulnerability Description	A denial of service vulnerability exists in OpenSSL. The vulnerability is due to a null pointer dereference that occurs when an OpenSSL application receives and processes a Client Certificate and a crafted Client Key Exchange handshake message. A remote, unauthenticated attacker can exploit this vulnerability by sending a crafted handshake message to a vulnerable server application. Successful exploitation will cause the server application to crash, resulting in 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 OpenSSL DHE Client Key Exchange 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: OpenSSL Enforcement Violation.
Attack Information: OpenSSL DHE Client Key Exchange Denial of Service