spice-xpi is vulnerable to arbitrary code execution. The vulnerability exists as an uninitialized pointer use flaw was found in the SPICE Firefox plug-in. If a user were tricked into visiting a malicious web page with Firefox while the SPICE plug-in was enabled, it could cause Firefox to crash or, possibly, execute arbitrary code with the privileges of the user running Firefox.
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
access.redhat.com/errata/RHSA-2011:0427
access.redhat.com/security/updates/classification/#moderate
bugzilla.redhat.com/attachment.cgi?id=487006&action=diff
bugzilla.redhat.com/show_bug.cgi?id=689931
exchange.xforce.ibmcloud.com/vulnerabilities/66777