Exchange Zero Day Vulnerability & The Way Forward

Many of you probably have heard about Microsoft’s release of patches for multiple different on-premises Microsoft Exchange Server zero-day vulnerabilities that are being exploited by a nation-state affiliated group.

The vulnerabilities exist in on-premises Exchange Servers 2010, 2013, 2016, and 2019.  Exchange Online is not affected. We wanted to ensure you were aware of the situation.

Microsoft highly recommends that you take immediate action to apply the patches for any on-premises Exchange deployments. The priority should be servers which are accessible from the internet (e.g., servers publishing Outlook on the web/OWA and ECP).

Your organization should move to the latest Exchange Cumulative Updates and then install the relevant security updates on each Exchange Server

  • You can use the Exchange Server Health Checker script, which can be downloaded from GitHub (use the latest release).
  • Running this script will tell you if you are behind on your on-premises Exchange Server updates (note that the script does not support Exchange Server 2010).
  • We also recommend that your security team assess whether or not the vulnerabilities were being exploited by using the Indicators of Compromise we shared here

Lastly, we suggest you contact our consultant to explore establishing a path to Microsoft 365, Exchange online and Zero Trust security so you can reap the benefits of the most secure version of exchange, cloud powered security and so much more ​