The s_mp_div function in lib/freebl/mpi/mpi.c in Mozilla Network Security Services (NSS)…
Priority LOW 35CWE-310Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
EPSS 0.0316 88th percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:* | 42.1 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:* | 13.1 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:* | 13.2 | Vulnerable | openSUSE |
| cpe:2.3:a:mozilla:nss:*:*:*:*:*:*:*:* | up to 3.20.1 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | up to 43.0.4 | Vulnerable | Mozilla |
- cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:* Versions 42.1 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:* Versions 13.1 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:* Versions 13.2 Vulnerable ·openSUSE
- cpe:2.3:a:mozilla:nss:*:*:*:*:*:*:*:* Versions up to 3.20.1 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions up to 43.0.4 Vulnerable ·Mozilla
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Timeline
- 2026-10-02 Threatist record created from CVE-2016-1938
- 2026-10-03 Alias added: GHSA-xp2m-37gc-hr6h
References
Advisory 14
- DSA-3688
- GLSA-201701-46
- http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
- USN-2903-2
- USN-2880-1
- USN-2903-1
- USN-2880-2
- https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes
- SUSE-SU-2016:0338
- http://www.mozilla.org/security/announce/2016/mfsa2016-07.html
- USN-2973-1
- openSUSE-SU-2016:0309
- GLSA-201605-06
- openSUSE-SU-2016:0306
Other 6
- https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c
- https://blog.fuzzing-project.org/37-Mozilla-NSS-Wrong-calculation-results-in-mp_div-and-mp_exptmod.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=1194947
- https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c
- https://bugzilla.mozilla.org/show_bug.cgi?id=1190248
- https://hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.c
Sources
- CVE-2016-1938 · CVE Program
- CVE-2016-1938 · NVD
- FIRST EPSS
- GHSA-xp2m-37gc-hr6h · GitHub Advisory Database · CC BY 4.0
- CVE-2016-1938 · Red Hat security data · CC BY 4.0
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