Memory safety bugs were reported in Firefox 50.1 and Firefox ESR 45.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.
http://rhn.redhat.com/errata/RHSA-2017-0190.html
http://rhn.redhat.com/errata/RHSA-2017-0238.html
http://www.securityfocus.com/bid/95762
http://www.securitytracker.com/id/1037693
https://security.gentoo.org/glsa/201702-13
https://security.gentoo.org/glsa/201702-22
https://www.debian.org/security/2017/dsa-3771
https://www.debian.org/security/2017/dsa-3832
https://www.mozilla.org/security/advisories/mfsa2017-01/
Source: MITRE
Published: 2018-06-11
Updated: 2018-08-02
Type: CWE-119
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