Serv-U FTP Server before 6.1.0.4 allows attackers to cause a denial of service (crash) via (1) malformed packets and possibly other unspecified issues with unknown impact and attack vectors including (2) use of "~" in a pathname, and (3) memory consumption of the daemon. NOTE: it is not clear whether items (2) and above are vulnerabilities.
http://www.vupen.com/english/advisories/2005/2267
http://www.serv-u.com/releasenotes.asp
http://www.securityfocus.com/bid/15273