The HTMLMediaElement::loadResource function in html/HTMLMediaElement.cpp in WebCore in WebKit before r49480, as used in Apple Safari before 4.0.4 on Mac OS X, does not perform the expected callbacks for HTML 5 media elements that have external URLs for media resources, which allows remote attackers to trigger sub-resource requests to arbitrary web sites via a crafted HTML document, as demonstrated by an HTML e-mail message that uses a media element for X-Confirm-Reading-To functionality, aka rdar problem 7271202.
lists.apple.com/archives/security-announce/2009/Nov/msg00001.html
lists.apple.com/archives/security-announce/2010/Feb/msg00000.html
lists.fedoraproject.org/pipermail/package-announce/2010-July/044023.html
lists.fedoraproject.org/pipermail/package-announce/2010-July/044031.html
lists.opensuse.org/opensuse-security-announce/2011-01/msg00006.html
osvdb.org/59941
secunia.com/advisories/37346
secunia.com/advisories/40557
secunia.com/advisories/41856
secunia.com/advisories/43068
support.apple.com/kb/HT3949
support.apple.com/kb/HT4013
threatpost.com/en_us/blogs/apple-patches-critical-safari-vulnerabilities-111109
trac.webkit.org/changeset/49480
www.mandriva.com/security/advisories?name=MDVSA-2011:039
www.securityfocus.com/bid/36996
www.securitytracker.com/id?1023167
www.ubuntu.com/usn/USN-1006-1
www.vupen.com/english/advisories/2009/3217
www.vupen.com/english/advisories/2010/1801
www.vupen.com/english/advisories/2010/2722
www.vupen.com/english/advisories/2011/0212
www.vupen.com/english/advisories/2011/0552
bugzilla.redhat.com/show_bug.cgi?id=525791
exchange.xforce.ibmcloud.com/vulnerabilities/54242