Check Point Advisories

TLS and SSL Diffie-Hellman Key Downgrade Weakness (CVE-2015-1716; CVE-2015-4000)

Vulnerability
Protection

Check Point Reference:	CPAI-2015-0586
Date Published:	20 May 2015
Severity:	N/A
Last Updated:	Sunday 03 December, 2017
Source:	Weak-Diffie-Hellman
Industry Reference:	CVE-2015-1716 CVE-2015-4000
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	SSL and TLS clients and servers.
Vulnerability Description	A vulnerability has been detected in the way TLS protocol handles weak, legacy cipher suites. An attacker might leverage this vulnerability to intercept secure communications.

Protection Overview

This protection may be used to prevent attacks exploiting the Logjam 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 TLS and SSL Diffie-Hellman Key Downgrade Weakness 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: SSL Enforcement Violation.
Attack Information: TLS and SSL Diffie-Hellman Key Downgrade Weakness