Safari after 2.0 in Apple Mac OS X 10.3.9 allows remote attackers to bypass domain restrictions via crafted web archives that cause Safari to render them as if they came from a different site.
http://www.ciac.org/ciac/bulletins/p-312.shtml
http://www.auscert.org.au/5509
http://secunia.com/advisories/16920/
http://lists.apple.com/archives/security-announce/2005/Sep/msg00002.html