The s_mp_div function in lib/freebl/mpi/mpi.c in Mozilla Network Security Services (NSS) before 3.21, as used in Mozilla Firefox before 44.0, improperly divides numbers, which might make it easier for remote attackers to defeat cryptographic protection mechanisms by leveraging use of the (1) mp_div or (2) mp_exptmod function.
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00002.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00010.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1190248
https://bugzilla.mozilla.org/show_bug.cgi?id=1194947
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes
https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c
https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c
https://hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.c
https://security.gentoo.org/glsa/201605-06
https://security.gentoo.org/glsa/201701-46
http://www.debian.org/security/2016/dsa-3688
http://www.mozilla.org/security/announce/2016/mfsa2016-07.html
http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
http://www.securitytracker.com/id/1034825
http://www.ubuntu.com/usn/USN-2880-1
http://www.ubuntu.com/usn/USN-2880-2
http://www.ubuntu.com/usn/USN-2903-1