Mozilla Firefox 2.0.0.1 and earlier does not prompt users before saving bookmarklets, which allows remote attackers to bypass the same-domain policy by tricking a user into saving a bookmarklet with a data: scheme, which is executed in the context of the last visited web page.
archives.neohapsis.com/archives/fulldisclosure/2007-02/0490.html
lcamtuf.coredump.cx/ffbook
lcamtuf.coredump.cx/ffbook/
osvdb.org/33803
securityreason.com/securityalert/2304
www.heise-security.co.uk/news/85728
www.securityfocus.com/archive/1/460885/100/0/threaded
www.securityfocus.com/archive/1/460890/100/0/threaded
www.securityfocus.com/archive/1/460896/100/0/threaded
www.securityfocus.com/archive/1/461021/100/0/threaded
www.securityfocus.com/bid/22666
bugzilla.mozilla.org/show_bug.cgi?id=371179