UGH... we have to re-apply it... damn....
Installing the Updated CU2
If you have already deployed CU2 to your Exchange 2013 servers you will need to download the new CU2 version and apply it to those servers. The process is the same as with any other CU deployment. This is an unfortunate situation for those that have already deployed CU2, however it is necessary so that future security updates can be applied to your servers when necessary.
You can download the new build here.
If you have not already deployed CU2 make sure you only deploy the new build. The old version has been removed from the Microsoft Download Center, and if you had already downloaded the first build of CU2 I recommend you delete those files to avoid someone accidentally using them to update your servers.