What systems are primarily at risk from the vulnerability? Domain controllers that are configured to act as a Kerberos Key Distribution Center (KDC) are primarily at risk.

...It is the cornerstone of President Obama's campaign theme about limiting the influence of special interests. During the campaign, Obama said many times that lobbyists would not run his White House, and the campaign delighted in tweaking rival John McCain for the former lobbyists who worked on McCain's campaign. Obama's ethics proposals specifically spelled out that former lobbyists would not be allowed to "work on regulations or contracts directly and substantially related to their prior employer for two years." On his first full day in office, Obama signed an executive order to that effect. But the order has a loophole — a "waiver" clause that allows former lobbyists to serve. That waiver clause has been used at least three times, and in some cases, the administration allows former lobbyists to serve without a waiver. After examining the administration's actions for the past two months, we have concluded that Obama has broken this promise. See Promise No. 240 for the full details.

This is one of those rare occasions where it's actually worked because the loser has accepted the ruling rather than saying "Okay, I lost, but I don't care, I'm going to carry on as I was anyway" or alternatively, "Fuck that, I'm not even going to go to that court because deep down I know I'm wrong and know I'll lose", the latter of which is what Argentina has done each time the UK has offered to let the court rule on the Falklands for example.