CVE-2016-1938: mozilla firefox Cryptographic Issues
Vulnerability summary
CVE-2016-1938 is a medium (CVSS 6.5) Cryptographic Issues vulnerability in mozilla firefox. EPSS estimates a 3.16% chance of exploitation in the next 30 days, higher than 88% of scored vulnerabilities.
Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 9 · Related 7Timeline
- 31-01-2016PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS trend
Probability
3.16%
Chance of exploitation in the next 30 days
Percentile
88%
Versus all other CVEs
30-day change
No change 0.00 pp
From 3.16% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu3 products
- firefox< 44.0+build3-0ubuntu0.14.04.1
- nss< 2:3.21-0ubuntu0.14.04.1
- thunderbird< 1:38.8.0+build1-0ubuntu0.14.04.1 | < 1:38.8.0+build1-0ubuntu0.16.04.1
Debian1 product
- nss< 2:3.21-1 | < 3.12.8-1+squeeze14
4 vendors · 8 products
References
30 links
- www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.htmlX Refsource CONFIRMThird Party Advisory
Show all 30 references
- developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notesX Refsource MISCVendor Advisory
- lists.opensuse.org/opensuse-security-announce/2016-02/msg00002.htmlVendor AdvisoryX Refsource SUSEThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2016-02/msg00001.htmlVendor AdvisoryX Refsource SUSEThird Party Advisory
- hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.cX Refsource CONFIRM