Microsoft has reached the end of extended support for server 2008 R2. Microsoft will no longer be releasing security patches for these operating systems as noted in the following documentation:
As noted in previously published post Windows 2008 Support is Ending; What's Next for Ektron Customers? we have historically suggested to customers to upgrade to later operating systems.
Moving forward, customers leveraging server 2008 R2 will need to upgrade to a an operating system of 2012 or higher that meets their Ektron version's system requirements. It is not supported to run a site on an operating system that cannot be considered secured.
A full list of system requirements can be found below for the various versions of Ektron.