Hm I forgot what CU nr this is. but it’s a September 2011 updates
Description of the cumulative update package for Office Communications Server 2007 R2, Communicator Web Access: September 2011
http://support.microsoft.com/kb/2603287/en-us?sd=rss&spid=924
Description of the cumulative update for Office Communications Server 2007 R2 Attendant: September 2011
http://support.microsoft.com/kb/2590692/en-us?sd=rss&spid=924
Description of the cumulative update for Office Communications Server 2007 R2, Core Components: September 2011
http://support.microsoft.com/kb/2603289/en-us?sd=rss&spid=924
Description of the cumulative update for Office Communications Server 2007 R2, Web Conferencing Server: September 2011
http://support.microsoft.com/kb/2603291/en-us?sd=rss&spid=924
Did I miss someone, wel if you just go to http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=19178 and download and run the ServerUpdateInstaller.exe you will find all the updates and install them.