The UCX POP server in HP TCP/IP services for OpenVMS 4.2 through 5.3 allows local users to truncate arbitrary files via the -logfile command line option, which overrides file system permissions because the server runs with the SYSPRV and BYPASS privileges.
http://www.iss.net/security_center/static/10236.php
http://archives.neohapsis.com/archives/compaq/2002-q4/0000.html
http://archives.neohapsis.com/archives/bugtraq/2002-10/0010.html