A use-after-free vulnerability can occur when reading an image observer during frame reconstruction after the observer has been freed. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
http://www.securityfocus.com/bid/100202
http://www.securitytracker.com/id/1039124
https://access.redhat.com/errata/RHSA-2017:2456
https://access.redhat.com/errata/RHSA-2017:2534
https://bugzilla.mozilla.org/show_bug.cgi?id=1376087
https://security.gentoo.org/glsa/201803-14
https://www.debian.org/security/2017/dsa-3928
https://www.debian.org/security/2017/dsa-3968
https://www.mozilla.org/security/advisories/mfsa2017-18/
Source: MITRE
Published: 2018-06-11
Updated: 2018-08-03
Type: CWE-416
Base Score: 7.5
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 10
Severity: HIGH
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 3.9
Severity: CRITICAL