A quick update to keep everyone informed on important Microsoft Exchange security updates:

May 11, 2021 – Microsoft Exchange Server vulnerability – this time it is a security feature bypass and is one of the Exchange vulnerabilities that was found during PWN2OWN 2021.

Microsoft has rated this as Exploitation Less Likely on the latest software release on the Exploitability Index 

https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-microsoft-exchange-server-2019-2016-and-2013-may-11-2021-kb5003435-028bd051-b2f1-4310-8f35-c41c9ce5a2f1

The Security Update (SU) is available from Windows Update. If downloading and applying manually, ensure you are at an elevated command prompt and follow the included instructions.  

For convenience, here are direct links to the Microsoft downloads for the latest Exchange versions:

We have not encountered any issues with installing the Microsoft Security Updates. We suggest that you proceed with applying the patches if you have not already.  If you encounter any post-install issues, please email to create a priority support ticket by emailing us at support@messageware.com