The UN has its problems with corruption as noted on this website.

The United States led Civilian Provincial Authority in Iraq also lost billions of US$ to corruption

(I refer you to the article by CSmonitor:
” Corruption in Iraq under US-led CPA may dwarf UN oil-for-food scandal.” http://www.csmonitor.com/2005/0407/dailyUpdate.html

Surely, having presided over all the corruption in the CPA, the US government must have some lessons learned for the UN?

Seriously.