Cryptographic issues in developer.mozilla nss

1) Cryptographic issues

EUVDB-ID: #VU32328

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-1938

CWE-ID: CWE-310 - Cryptographic Issues

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

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.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla NSS: 3.13.4 - 3.52.1

External links

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
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.securityfocus.com/bid/81955
http://www.securityfocus.com/bid/91787
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
http://www.ubuntu.com/usn/USN-2903-2
http://www.ubuntu.com/usn/USN-2973-1
http://blog.fuzzing-project.org/37-Mozilla-NSS-Wrong-calculation-results-in-mp_div-and-mp_exptmod.html
http://bugzilla.mozilla.org/show_bug.cgi?id=1190248
http://bugzilla.mozilla.org/show_bug.cgi?id=1194947
http://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes
http://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c
http://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c
http://hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.c
http://security.gentoo.org/glsa/201605-06
http://security.gentoo.org/glsa/201701-46

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.