Check Point Advisories

Microsoft Windows Network File System Denial of Service (CVE-2020-17047)

Vulnerability
Protection

Check Point Reference:	CPAI-2020-1188
Date Published:	16 Nov 2020
Severity:	High
Last Updated:	Monday 16 November, 2020
Source:
Industry Reference:	CVE-2020-17047
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Microsoft Windows 7 Microsoft Windows 8.1 Microsoft Windows 10 Microsoft Windows RT 8.1 Microsoft Windows Server 2008 Microsoft Windows Server 2008 R2 Microsoft Windows Server 2012 Microsoft Windows Server 2012 R2 Microsoft Windows Server 2016 Microsoft Windows Server 2019 Microsoft Windows Server version 1803 (Server Core Installation) Microsoft Windows Server version 1903 (Server Core installation) Microsoft Windows Server version 1909 (Server Core installation) Microsoft Windows Server version 2004 (Server Core installation)
Vulnerability Description	A denial of service vulnerability has been reported in Windows Network File System. The vulnerability is due to improper handling of crafted RPC packets. A remote attacker can exploit this vulnerability by sending malicious RPC calls to a targe 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 Network File System Denial of Service (CVE-2020-17047) 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: NFS Protection Violation.
Attack Information: Microsoft Windows Network File System Denial of Service (CVE-2020-17047)