Microsoft has released patches to fix numerous vulnerabilities in the February 2023 Patch Tuesday release including remote code execution in Exchange Server.

Official announcement can be found here.

Microsoft has released Security Updates (SUs) for vulnerabilities found in:

  • Exchange Server 2013
  • Exchange Server 2016
  • Exchange Server 2019

To learn more about these vulnerabilities, see the following Common Vulnerabilities and Exposures (CVE):

Issues that are fixed in this update:

Export-UMPrompt fails with InvalidResponseException

Edge Transport service returns an “EseNtOutOfSessions” Exception

Some Exchange services do not start automatically after installing January 2023 Security Update

Data source returns incorrect checkpoint depth

Serialization fails while tried accessing Mailbox Searches in ECP

Transport delivery service mishandles iCAL events

SUs are available for the following specific versions of Exchange Server:

  • Exchange Server 2013 CU23 (note that support and availability of SUs end on April 11, 2023)
  • Exchange Server 2016 CU23
  • Exchange Server 2019 CU11 and CU12 

The February 2023 SUs address vulnerabilities responsibly reported to Microsoft by security partners and found through Microsoft’s internal processes. Although we are not aware of any active exploits in the wild, our recommendation is to immediately install these updates to protect your environment.

These vulnerabilities affect Exchange Server. Exchange Online customers are already protected from the vulnerabilities addressed in these SUs and do not need to take any action other than updating Exchange servers in their environment.

More details about specific CVEs can be found in the Security Update Guide (filter on Exchange Server under Product Family).

Update installation

Known issues with this release

Issues resolved in this release

Reach out to Messageware to improve Microsoft Exchange Server Security

If you are not protecting all the protocols used by your Exchange Server, you’re putting your company at a higher risk of a data breach.

Security incidents happen frequently. They cause disruption, loss of data and potentially risk the reputation of your company. However, if you implement these steps, you’re doing more than most other companies.

Have you heard about Messageware’s EPG that offers advanced Exchange Server security to protect organizations from a variety of logon and password attacks, as well as extensive real-time reporting and alerts of suspicious logon activity? Click here to learn more.