Description of the security update for Microsoft Exchange: December 12, 2017

This security update was released to address a known issue in security update 4036108 in which customers that are using split DNS may encounter problems that affect Calendar Sharing. This update removes the fix for this vulnerability. 

• We are aware of some reports that Exchange services may remain in a disabled state after you install this security update. If this occurs, the update is installed correctly. However, the service control scripts encounter a problem when they try to return Exchange services to its usual state. To resolve this issue, use Services Manager to restore the startup type to Automatic, and then start the affected Exchange services manually.

• When you try to manually install this security update in "normal mode" (not running the update as an administrator) and by double-clicking the update file (.msp), some files are not correctly updated. When this issue occurs, you do not receive an error message or any indication that the security update is not correctly installed. Also, Outlook Web Access (OWA) and the Exchange Control Panel (ECP) may stop working. This issue occurs on servers that are using UAC (user account control). The issue occurs because the security update does not correctly stop certain Exchange-related services. To avoid this issue, run the security update in elevated mode as an administrator. To do this, right click the update file, and then click Run as administrator.

Method 1: Microsoft Update

Method 2: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

Method 3: Microsoft Download Center

Security update deployment information

For deployment information about this update, see security update deployment information: December 12, 2017.