Stack-based buffer overflow in the VPN daemon (vpnd) for Mac OS X before 10.3.9 allows local users to execute arbitrary code via a long -i (Server_id) argument.
http://www.us-cert.gov/cas/techalerts/TA05-136A.html
http://www.kb.cert.org/vuls/id/706838
http://lists.apple.com/archives/security-announce/2005/May/msg00001.html
http://lists.apple.com/archives/security-announce/2005/Jun/msg00000.html