If you have a Windows server, now is the time to patch it! This one is really bad since you can become an Domain Admin in one click. If you have been living under a rock, there is a flaw in the way that Netlogon works in Windows which allows you to impersonate the domain controller sufficiently to be able to add yourself as a Domain Admin to the domain.
I expect to see a whole wave of ransomware attacks before everyone gets patched.