SharePoint 2013 Rollup Update for the December 2013 Cumulative Update Packaging

The following change was made to the December 2013 Cumulative Update from the previous SharePoint Server 2013 rollup updates. Previously, SharePoint 2013 Cumulative Updates included both the executable and the .CAB file in the same self-extracting executable download. Due to the file size, the SharePoint Server 2013 package has been divided into two separate downloads in December 2013. One package contains the executable file (identified as ubersrv2013kb2850024fullfilex64glb), while the other contains the .CAB file (identified as ubersrv_1). Both are necessary and must be extracted to the same folder to successfully install the update. Both are available via the same Hotfix Download Available link in the KB article for the December 2013 SharePoint Server Cumulative Update release.

For more information:
http://blogs.technet.com/b/office_sustained_engineering/archive/2013/12/20/change-sharepoint-2013-rollup-update-for-the-december-2013-cumulative-update-packaging.aspx