firefox/thunderbird is vulnerable to arbitrary code execution. Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause Firefox to crash or, potentially, execute arbitrary code with the privileges of the user running Firefox.
lists.opensuse.org/opensuse-security-announce/2015-01/msg00024.html
lists.opensuse.org/opensuse-security-announce/2015-07/msg00031.html
www.debian.org/security/2014/dsa-3090
www.debian.org/security/2014/dsa-3092
www.mozilla.org/security/announce/2014/mfsa2014-88.html
www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
www.securityfocus.com/bid/71395
access.redhat.com/articles/1283153
access.redhat.com/security/updates/classification/#critical
bugzilla.mozilla.org/show_bug.cgi?id=1085175
rhn.redhat.com/errata/RHSA-2014-1919.html
security.gentoo.org/glsa/201504-01
www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/#firefoxesr31.3