WebKit in Apple Mac OS X 10.3.9, 10.4.9 and later, and iPhone before 1.0.1 performs an "invalid type conversion", which allows remote attackers to execute arbitrary code via unspecified frame sets that trigger memory corruption.
https://exchange.xforce.ibmcloud.com/vulnerabilities/35019
http://www.vupen.com/english/advisories/2007/2731
http://www.vupen.com/english/advisories/2007/2316
http://www.vupen.com/english/advisories/2007/2296
http://www.securitytracker.com/id?1018281
http://www.securityfocus.com/bid/24597
http://www.kb.cert.org/vuls/id/389868
http://secunia.com/advisories/26287
http://secunia.com/advisories/25786
http://lists.apple.com/archives/Security-announce/2007/Jun/msg00003.html