Description
WordPress is prone to a vulnerability which can be exploited by malicious people to cause a Denial of Service. The vulnerability is caused due to the 'wp-register.php' script against which attackers can trigger repeated registration to cause a high CPU load, potentially resulting in a Denial of Service. WordPress versions 2.0.1 and prior are all vulnerable.
Remediation
Update to WordPress version 2.0.2 or latest
References
http://www.securityfocus.com/archive/1/427152/30/0/threaded
http://packetstormsecurity.org/files/44497/HYSA-2006-005.txt