KLA12169 Multiple vulnerabilities in Microsoft Exchange Server

Multiple vulnerabilities were found in Microsoft Exchange Server. Malicious users can exploit these vulnerabilities to execute arbitrary code, spoof user interface, bypass security restrictions.

Below is a complete list of vulnerabilities:

1. A remote code execution vulnerability in Microsoft Exchange Server can be exploited remotely to execute arbitrary code.
2. A spoofing vulnerability in Microsoft Exchange Server can be exploited remotely to spoof user interface.
3. A security feature bypass vulnerability in Microsoft Exchange Server can be exploited remotely to bypass security restrictions.

Original advisories

CVE-2021-31198

CVE-2021-31209

CVE-2021-31207

CVE-2021-31195

Exploitation

This vulnerability can be exploited by the following malware:

https://threats.kaspersky.com/en/threat/Exploit.Win32.ProxyShell/

Related products

Microsoft-Exchange-Server

CVE list

CVE-2021-31198 critical

CVE-2021-31209 high

CVE-2021-31207 high

CVE-2021-31195 high

KB list

5003435

Solution

Install necessary updates from the KB section, that are listed in your Windows Update (Windows Update usually can be accessed from the Control Panel)

Impacts

• ACE

Arbitrary code execution. Exploitation of vulnerabilities with this impact can lead to executing by abuser any code or commands at vulnerable machine or process.

• SB

Security bypass. Exploitation of vulnerabilities with this impact can lead to performing actions restricted by current security settings.

• SUI

Spoof user interface. Exploitation of vulnerabilities with this impact can lead to changes in user interface to beguile user into inaccurate behavior.

Affected Products

• Microsoft Exchange Server 2016 Cumulative Update 20Microsoft Exchange Server 2019 Cumulative Update 8Microsoft Exchange Server 2019 Cumulative Update 9Microsoft Exchange Server 2013 Cumulative Update 23Microsoft Exchange Server 2016 Cumulative Update 19