The Bonjour functionality in iChat in Apple Mac OS X 10.3.9 allows remote attackers to cause a denial of service (persistent application crash) via unspecified vectors, possibly related to CVE-2007-0614.
http://www.securitytracker.com/id?1017661
http://www.kb.cert.org/vuls/id/836024
http://secunia.com/advisories/24198
http://lists.apple.com/archives/Security-announce/2007/Feb/msg00000.html