Buffer overflow in su in Tru64 Unix 5.x allows local users to gain root privileges via a long username and argument.
http://www.securityfocus.com/bid/5272
http://www.kb.cert.org/vuls/id/229867
http://www.iss.net/security_center/static/9640.php
http://marc.info/?l=bugtraq&m=102709593117171&w=2
http://archives.neohapsis.com/archives/tru64/2002-q3/0019.html