http://kwsupport.com/2013/03/hotfix-rol ... 08-r2-sp1/
I found out about this after my company's internal vulnerability scanner complained that we didn't have this patch installed. Well, yeah, it wasn't published via Microsoft Update or WSUS.
We deployed it to our AD servers a bit at a time since we could reboot them at will. Well, that caused Exchange to stop talking to AD so Outlook couldn't authenticate anyone anymore. So we installed it on Exchange and rebooted and all was good again. What can I say, we're fast and loose like that. Just a heads up in case someone else deploys this on "safe" servers during business hours.
We also deployed it on Win7 boxes as well. So far no ill effects. Heck, I even installed it on my home computer. I didn't see anyone else mention it so I figured I'd spread the word.