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
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.
- Published
- Jan 31, 2016
- Updated
- Jun 16, 2026
- EPSS
- 3.2% · 87th percentile
- CWE
- CWE-310
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Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 3.2%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mozilla | nss | cpe:2.3:a:mozilla:nss |
| mozilla | firefox | cpe:2.3:a:mozilla:firefox |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
| opensuse | opensuse | cpe:2.3:o:opensuse:opensuse |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mozilla firefoxup to 43.0.4 inclusive
- mozilla nssup to 3.20.1 inclusive
- opensuse leap42.1
- opensuse opensuse13.1
- opensuse opensuse13.2
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | nss | before 2:3.21-1 | 2:3.21-1 |
| Debian:6.0 | nss | before 3.12.8-1+squeeze14 | 3.12.8-1+squeeze14 |
| Debian:7 | nss | before 2:3.14.5-1+deb7u6 | 2:3.14.5-1+deb7u6 |
| Debian:8 | nss | before 2:3.26-1+debu8u1 | 2:3.26-1+debu8u1 |
| SUSE:Linux Enterprise Desktop 11 SP3 | MozillaFirefox-branding-SLED | before 38-18.24 | 38-18.24 |
| SUSE:Linux Enterprise Desktop 12 | mozilla-nss | before 3.20.2-37.1 | 3.20.2-37.1 |
| SUSE:Linux Enterprise Desktop 12 | MozillaFirefox | before 38.6.0esr-57.3 | 38.6.0esr-57.3 |
| SUSE:Linux Enterprise Desktop 12 | MozillaFirefox-branding-SLE | before 31.0-20.1 | 31.0-20.1 |
| SUSE:Linux Enterprise Server 11 SP2-LTSS | mozilla-nss | before 3.20.2-17.5 | 3.20.2-17.5 |
| SUSE:Linux Enterprise Server 11 SP2-LTSS | MozillaFirefox | before 38.6.1esr-33.1 | 38.6.1esr-33.1 |
| SUSE:Linux Enterprise Server 11 SP2-LTSS | MozillaFirefox-branding-SLED | before 38-15.58 | 38-15.58 |
| SUSE:Linux Enterprise Software Development Kit 11 SP3 | mozilla-nss | before 3.20.2-25.2 | 3.20.2-25.2 |
| SUSE:Linux Enterprise Software Development Kit 11 SP3 | MozillaFirefox | before 38.6.0esr-31.3 | 38.6.0esr-31.3 |
Same product
mozilla: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-43527NSS (Network Security Services) versions prior to 3.73 or 3.68.1 ESR are vulnerable to a heap overflow when handling DER-encoded DSA or RSA-44Plan
- CVE-2020-12403A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55.36Monitor
- CVE-2016-5285A Null pointer dereference vulnerability exists in Mozilla Network Security Services due to a missing NULL check in PK11_SignWithSymKey / ss31Monitor
- CVE-2023-4421The NSS code used for checking PKCS#1 v1.5 was leaking information useful in mounting Bleichenbacher-like attacks.26Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:nss | 2:3.21-1 · Debian:12 | Package registry (OSV) |
| suse:mozilla-nss | 3.20.2-25.2 · SUSE:Linux Enterprise Software Development Kit 11 SP3 | Package registry (OSV) |
| suse:MozillaFirefox | 38.6.0esr-31.3 · SUSE:Linux Enterprise Software Development Kit 11 SP3 | Package registry (OSV) |
| suse:MozillaFirefox-branding-SLE | 31.0-20.1 · SUSE:Linux Enterprise Desktop 12 | Package registry (OSV) |
| suse:MozillaFirefox-branding-SLED | 38-18.24 · SUSE:Linux Enterprise Desktop 11 SP3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-310 · Cryptographic IssuesCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2016-02/msg00001.html
- lists.opensuse.org/opensuse-security-announce/2016-02/msg00002.html
- lists.opensuse.org/opensuse-security-announce/2016-02/msg00010.html
- www.debian.org/security/2016/dsa-3688
- www.mozilla.org/security/announce/2016/mfsa2016-07.html
- www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
- www.securityfocus.com/bid/81955
- www.securityfocus.com/bid/91787
- www.securitytracker.com/id/1034825
- www.ubuntu.com/usn/USN-2880-1
- www.ubuntu.com/usn/USN-2880-2
- www.ubuntu.com/usn/USN-2903-1
- www.ubuntu.com/usn/USN-2903-2
- www.ubuntu.com/usn/USN-2973-1
- blog.fuzzing-project.org/37-Mozilla-NSS-Wrong-calculation-results-in-mp_div-and-mp_exptmod.html
- bugzilla.mozilla.org/show_bug.cgi?id=1190248
- bugzilla.mozilla.org/show_bug.cgi?id=1194947
- developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes
- github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c
- github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c
Vendor advisories and official records. Exploit/PoC links are deliberately left out.