Check Point Advisories

Microsoft Windows DNS Server Denial of Service (CVE-2017-0171)

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0365
Date Published:	9 May 2017
Severity:	High
Last Updated:	Tuesday 09 May, 2017
Source:	Microsoft CVE-2017-0171
Industry Reference:	CVE-2017-0171
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) Windows Server 2008 R2 for x64-based Systems Service Pack 1 Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) Windows Server 2012 Windows Server 2012 (Server Core installation) Windows Server 2012 R2 Windows Server 2012 R2 (Server Core installation) Windows Server 2016 Windows Server 2016 (Server Core installation) Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2008 for x64-based Systems Service Pack 2 Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
Vulnerability Description	A denial of service vulnerability exists in Windows DNS servers. This vulnerability is due to a mishandling of malformed packets by the DNS servers. An attacker can exploit this vulnerability by sending a malformed packet to a Windows DNS server.

Protection Overview

This protection detects 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 Microsoft Windows DNS Server Denial of Service (CVE-2017-0171) 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: DNS Enforcement Violation.
Attack Information: Microsoft Windows DNS Server Denial of Service (CVE-2017-0171)