In order to exploit this vulnerability, a malicious RPC client must send a malformed RPC packet to a Windows 2000 server. On receiving the malformed RPC packet, the server stops responding to client requests.
This is a Denial of Service vulnerability which primarily affects Windows 2000 servers that are directly exposed on the Internet. A server behind a firewall that blocks ports 135-139 and 445 are not affected by this vulnerability.
RPC services and the functioning of the server can be restored after an attack by restarting the affected computer.
For more information about this vulnerability, read Microsoft Security Bulletin MS00-066.