The SPICE Firefox plug-in (spice-xpi) 2.4, 2.3, 2.2, and possibly other versions allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via vectors related to (1) plugin/nsScriptablePeer.cpp and (2) plugin/plugin.cpp, which trigger multiple uses of an uninitialized pointer.
secunia.com/advisories/44060
www.redhat.com/support/errata/RHSA-2011-0426.html
www.redhat.com/support/errata/RHSA-2011-0427.html
www.securityfocus.com/bid/47269
www.securitytracker.com/id?1025304
www.vupen.com/english/advisories/2011/0899
bugzilla.redhat.com/attachment.cgi?id=487006&action=diff
bugzilla.redhat.com/show_bug.cgi?id=689931
exchange.xforce.ibmcloud.com/vulnerabilities/66777