I bought a Fannie Mae 4 unit apartment building that was in foreclosure [by them] and it was AS IS. They completely neglect their held property's and allowed the pipes to freeze, numerous break In's resulting in stolen washer/dryers, refrigerators and the hot water heaters[yes the hot water heaters were stolen] and kicked in doors and broken windows.
I spent $13,000 just making the property livable.
Buying from Fannie Mae is not the same as buying from a private individual. It's just a case number on their list, they could not care less about the condition of the property.
The most important thing is having a good house inspection before you buy.