This update resolves the "IP Fragment Reassembly" security vulnerability in Windows 2000. Installing this update will minimize the negative effects that fragmented Internet Protocol (IP) datagrams could have on your computer's central processing unit (CPU). IP datagrams are a necessary part of network and Internet communication. If a continuous stream of fragmented IP datagrams with a particular malformation were sent to an affected computer, it could be made to devote most or all of its CPU availability to processing these fragments. The vulnerability would not allow a malicious user to compromise data on the computer or usurp administrative control over it.
For more information on this vulnerability, please visit Microsoft Security Bulletin MS00-029.