NSS: Errors in mp_div and mp_exptmod cryptographic functions
Published Jan 31, 2016
6.5
MEDIUMCVSS 3.0
EPSS 3.16%
Description
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.
Affected products
No data.
No data.
Red Hat Enterprise Linux 5
nss
Will not fix
Red Hat Enterprise Linux 6
nss-softokn
Will not fix
Red Hat Enterprise Linux 7
nss-softokn
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | nss | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | nss-softokn | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | nss-softokn | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
AV:N/AC:L/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.16% (0.03160) | 87.53th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.12% (0.03121) | 86.11th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.05% (0.01048) | 75.53th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.38% (0.02379) | 74.97th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.05% (0.01048) | 75.99th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.33% (0.00331) | 71.94th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.33% (0.00331) | 70.28th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.33% (0.00331) | 66.45th | v3 (v2023.03.01) |
| Mar 6, 2023 | 4.36% (0.04358) | 88.02th | v2 (v2022.01.01) |
| Apr 1, 2022 | 4.36% (0.04358) | 86.83th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.36% (0.04358) | 70.59th | v2 (v2022.01.01) |
References (27)
- http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00001.html vendor-advisoryx_refsource_SUSEThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00002.html vendor-advisoryx_refsource_SUSEThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00010.html vendor-advisoryx_refsource_SUSE
- http://www.debian.org/security/2016/dsa-3688 vendor-advisoryx_refsource_DEBIAN
- http://www.mozilla.org/security/announce/2016/mfsa2016-07.html x_refsource_CONFIRMVendor Advisory
- http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html x_refsource_CONFIRMThird Party Advisory
- http://www.securityfocus.com/bid/81955 vdb-entryx_refsource_BID
- http://www.securityfocus.com/bid/91787 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1034825 vdb-entryx_refsource_SECTRACK
- http://www.ubuntu.com/usn/USN-2880-1 vendor-advisoryx_refsource_UBUNTU
- http://www.ubuntu.com/usn/USN-2880-2 vendor-advisoryx_refsource_UBUNTU
- http://www.ubuntu.com/usn/USN-2903-1 vendor-advisoryx_refsource_UBUNTU
- http://www.ubuntu.com/usn/USN-2903-2 vendor-advisoryx_refsource_UBUNTU
- http://www.ubuntu.com/usn/USN-2973-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2016-1938 Vendor Advisory
- https://blog.fuzzing-project.org/37-Mozilla-NSS-Wrong-calculation-results-in-mp_div-and-mp_exptmod.html x_refsource_MISC
- https://bugzilla.mozilla.org/show_bug.cgi?id=1190248 x_refsource_CONFIRMIssue Tracking
- https://bugzilla.mozilla.org/show_bug.cgi?id=1194947 x_refsource_CONFIRMIssue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=1305159 Issue Tracking
- https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes x_refsource_MISCVendor Advisory
- https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c x_refsource_MISC
- https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c x_refsource_MISC
- https://hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.c x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2016-1938
- https://security.gentoo.org/glsa/201605-06 vendor-advisoryx_refsource_GENTOO
- https://security.gentoo.org/glsa/201701-46 vendor-advisoryx_refsource_GENTOO
- https://www.cve.org/CVERecord?id=CVE-2016-1938
Change history (0)
No recorded changes yet.