Check Point Advisories

Microsoft Exchange Server Security Feature Authentication Bypass (CVE-2021-31207)

Vulnerability
Protection

Check Point Reference:	CPAI-2021-0900
Date Published:	16 Dec 2021
Severity:	High
Last Updated:	Tuesday 03 January, 2023
Source:
Industry Reference:	CVE-2021-31207
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Exchange 2013 CU23 versions before 15.0.1497.15 Exchange 2016 CU19 versions before 15.1.2176.12 Exchange 2016 CU20 versions before 15.1.2242.5 Exchange 2019 CU8 versions before 15.2.792.13 Exchange 2019 CU9 versions before 15.2.858.9
Vulnerability Description	An authentication bypass vulnerability exists in Microsoft Exchange Server. Successful exploitation of this vulnerability would allow remote attackers to gain unauthorized access into the affected system.

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 R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the Microsoft Exchange Server Security Feature Authentication Bypass (CVE-2021-31207) 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: Windows SMB Protection Violation.
Attack Information: Microsoft Exchange Server Security Feature Authentication Bypass (CVE-2021-31207)