Directory traversal vulnerability in the IMAP server in ArGoSoft Mail Server Pro 1.8.8.1 allows remote authenticated users to create arbitrary folders via a .. (dot dot) in the RENAME command.
http://www.vupen.com/english/advisories/2006/0733
http://www.securityfocus.com/bid/16809
http://www.securityfocus.com/archive/1/425969/100/0/threaded