WebKitGTK+ is use-after-free. The attack is possible because it allows an attacker to execute arbitrary code or cause a denial of service (application crash) via vectors related to improper handling of MIME types by plug-ins.
code.google.com/p/chromium/issues/detail?id=50515
code.google.com/p/chromium/issues/detail?id=51835
googlechromereleases.blogspot.com/2010/08/stable-channel-update_19.html
lists.apple.com/archives/security-announce/2010//Nov/msg00002.html
lists.apple.com/archives/security-announce/2010//Nov/msg00003.html
lists.opensuse.org/opensuse-security-announce/2011-01/msg00006.html
secunia.com/advisories/41856
secunia.com/advisories/42314
secunia.com/advisories/43068
secunia.com/advisories/43086
support.apple.com/kb/HT4455
support.apple.com/kb/HT4456
www.mandriva.com/security/advisories?name=MDVSA-2011:039
www.redhat.com/support/errata/RHSA-2011-0177.html
www.securityfocus.com/bid/44200
www.ubuntu.com/usn/USN-1006-1
www.vupen.com/english/advisories/2010/2722
www.vupen.com/english/advisories/2010/3046
www.vupen.com/english/advisories/2011/0212
www.vupen.com/english/advisories/2011/0216
www.vupen.com/english/advisories/2011/0552
access.redhat.com/errata/RHSA-2011:0177
access.redhat.com/security/updates/classification/#moderate
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11909