Firefox, Firefox ESR and Thunderbird are vulnerable to use-after-free vulnerability. A remote unauthenticated attacker could exploit the vulnerable Image Observer
component to cause a system crash when reading an image observer during frame reconstruction resulting in denial of service conditions.
www.securityfocus.com/bid/100202
www.securitytracker.com/id/1039124
access.redhat.com/errata/RHSA-2017:2456
access.redhat.com/errata/RHSA-2017:2534
access.redhat.com/security/updates/classification/#critical
bugzilla.mozilla.org/show_bug.cgi?id=1376087
security.gentoo.org/glsa/201803-14
www.debian.org/security/2017/dsa-3928
www.debian.org/security/2017/dsa-3968
www.mozilla.org/en-US/security/advisories/mfsa2017-19/
www.mozilla.org/security/advisories/mfsa2017-18/
www.mozilla.org/security/advisories/mfsa2017-19/
www.mozilla.org/security/advisories/mfsa2017-20/