The local and remote desktop login screens in Microsoft Windows XP before SP2 and 2003 allow remote attackers to cause a denial of service (CPU and memory consumption) by repeatedly using the WinKey+"U" key combination, which causes multiple copies of Windows Utility Manager to be loaded more quickly than they can be closed when the copies detect that another instance is running.

The DoS flaw affects slower machines and those with less ram quicker than higher specification machines. On very hi-spec machines, the flaw does not seem to be exploitable.