The accept_connections function in the virtual private network daemon (vpnd) in Apple Mac OS X 10.5 before 10.5.4 allows remote attackers to cause a denial of service (divide-by-zero error and daemon crash) via a crafted load balancing packet to UDP port 4112.
http://lists.apple.com/archives/security-announce/2008//Jun/msg00002.html
http://secunia.com/advisories/27938
http://secunia.com/advisories/30802
http://support.apple.com/kb/HT2163
http://www.securityfocus.com/bid/26699
http://www.securitytracker.com/id?1019052
http://www.vupen.com/english/advisories/2007/4145
http://www.vupen.com/english/advisories/2008/1981/references