Check Point Advisories

OpenSSH sshd auth_passwd Denial of Service (CVE-2016-6515)

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0017
Date Published:	8 Jan 2017
Severity:	High
Last Updated:	Wednesday 11 January, 2017
Source:	OpenSSH
Industry Reference:	CVE-2016-6515
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	OpenSSH OpenSSH prior to 7.3
Vulnerability Description	A denial of service vulnerability has been discovered in OpenSSH. The vulnerability is due to not limiting the password length during authentication of users in the auth_passwd module. A remote, unauthenticated attacker could exploit this vulnerability by supplying a specially crafted password as input while authenticating via ssh. Successful exploitation of this vulnerability could result in overloading the server process causing denial of service.

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 OpenSSH sshd auth_passwd 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: SSH Protection Violation.
Attack Information: OpenSSH sshd auth_passwd Denial of Service