Race condition in the Mozilla Maintenance Service in Mozilla Firefox before 40.0 and Firefox ESR 38.x before 38.2 on Windows allows local users to write to arbitrary files and consequently gain privileges via vectors involving a hard link to a log file during an update.
https://www.exploit-db.com/exploits/37925/
https://security.gentoo.org/glsa/201605-06
https://bugzilla.mozilla.org/show_bug.cgi?id=1171518
http://www.securitytracker.com/id/1033372
http://www.securitytracker.com/id/1033247
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.mozilla.org/security/announce/2015/mfsa2015-84.html
http://lists.opensuse.org/opensuse-updates/2015-08/msg00031.html
http://lists.opensuse.org/opensuse-updates/2015-08/msg00030.html
http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00015.html
http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00014.html