Cumulative Update 2 for Exchange Server 2013 was re-released yesterday (07/29/2013)
New version of CU2 for Exchange 2013 RTM fixes a serious permission issue when moving modern public folders mailboxes around.
We wrote about this in article:
Regardless of whether you are using modern public folders, we strongly recommend upgrading to this build of Exchange 2013 RTM CU2.
New CU2 has build number: 15.0.712.24 (KB2859928)
and can be downloaded from Microsoft Download Center: