This update isn't available since Exchange Server 2013 Service Pack 1 (2926248) was released on February 25, 2014. You can install the latest Exchange Server 2013 update to get the improvement in Cumulative Update 2.
This article describes Cumulative Update 2 for Microsoft Exchange Server 2013 that provides the latest fixes for Exchange Server 2013 and contains stability and performance improvements. This update enables you to install Exchange Server 2013 in your existing Exchange Server 2010 or Exchange Server 2007 organization.
The Cumulative Update 2 package can be used to perform a new installation, or to upgrade an existing Exchange Server 2013 installation to Cumulative Update 2.
You do not need to install Cumulative Update 1 for Exchange Server 2013 when you are installing Cumulative Update 2.
Exchange Server 2013 setup will identify any missing prerequisites.
You have to restart the computer after you apply this cumulative update package.
You do not have to make any changes to the registry after you apply this cumulative update package.
After you install this cumulative update package, you cannot uninstall the cumulative update package to revert to an earlier version of Exchange 2013. If you uninstall this cumulative update package, Exchange 2013 is removed from the server.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates