Skip to content
Fencer Intel
medium 4.3

CVE-2015-2721 json

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 3…

published 11y ago modified 4mo ago also EUVD-2015-2811

cvss
4.3
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a "SMACK SKIP-TLS" issue.

Patch / fix

  • nss Debian 14, Debian 13, Debian 12 2:3.19.1-1

debian advisories DEBIAN-CVE-2015-2721

  • nss Ubuntu 14.04 LTS 2:3.19.2-0ubuntu0.14.04.1
  • firefox Ubuntu 14.04 LTS 39.0+build5-0ubuntu0.14.04.1
  • thunderbird Ubuntu 14.04 LTS 1:31.8.0+build1-0ubuntu0.14.04.1

ubuntu advisories UBUNTU-CVE-2015-2721

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nss RHEL 5 3.19.1-1.el5_11
  • nss-tools RHEL 5 3.19.1-1.el5_11
  • nss RHEL 6 3.19.1-3.el6_6
  • nss RHEL 7 3.19.1-3.el7_1
  • nss RHEL 7 3.19.1-3.ael7b_1
  • nss-util RHEL 6 3.19.1-1.el6_6
  • nss-util RHEL 7 3.19.1-1.el7_1
  • nss-util RHEL 7 3.19.1-1.ael7b_1

red hat advisories RHSA-2015:1664RHSA-2015:1185

  • mozilla-nss SLES 11 SP2-LTSS, SLES 11 SP1-TERADATA, SLES 11 SP1-LTSS 3.19.2.0-0.7.1
  • firefox-gcc47 SLES 11 SP2-LTSS, SLES 11 SP1-TERADATA, SLES 11 SP1-LTSS 4.7.2_20130108-0.37.2
  • MozillaFirefox SLES 11 SP2-LTSS, SLES 11 SP1-TERADATA, SLES 11 SP1-LTSS 38.2.0esr-10.1
  • MozillaFirefox-branding-SLED SLES 11 SP2-LTSS, SLES 11 SP1-TERADATA, SLES 11 SP1-LTSS 31.0-0.5.7.11
  • mozilla-nss SLES 11 SP4, SLES 11 SP3-TERADATA, SLES 11 SP3 +6 more 3.19.2_CKBI_1.98-0.10.1
  • mozilla-nspr SLES 11 SP4, SLES 11 SP3-TERADATA, SLES 11 SP3 +6 more 4.10.8-0.5.1
  • MozillaFirefox SLES 11 SP4, SLES 11 SP3-TERADATA, SLES 11 SP3 +6 more 31.8.0esr-0.10.1
  • mozilla-nss SLES for SAP 12, SLES 12, SLED 12 +1 more 3.19.2_CKBI_1.98-21.1

suse advisories SUSE-SU-2015:1449-1SUSE-SU-2015:1268-1SUSE-SU-2015:1268-2SUSE-SU-2015:1269-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1
  • MozillaThunderbird openSUSE Tumbleweed 45.5.1-1.1
  • mozilla-nss openSUSE Tumbleweed 3.26.2-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1openSUSE-SU-2024:10230-1openSUSE-SU-2024:10451-1

Is CVE-2015-2721 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-2721 updated cvss 5.1

NSS: incorrectly permited skipping of ServerKeyExchange (MFSA 2015-71)

  • Red Hat Enterprise Linux (v. 5 server) nss 3.19.1-1.el5_11, nss-tools 3.19.1-1.el5_11
    fixed: vendor fix RHSA-2015:1664
  • Red Hat Enterprise Linux Client (v. 7) nss 3.19.1-3.el7_1, nss-util 3.19.1-1.el7_1, nss-tools 3.19.1-3.el7_1, nss-sysinit 3.19.1-3.el7_1 Red Hat Enterprise Linux Client Optional (v. 7) nss-devel 3.19.1-3.el7_1, nss-debuginfo 3.19.1-3.el7_1, nss-util-devel 3.19.1-1.el7_1, nss-pkcs11-devel 3.19.1-3.el7_1, nss-util-debuginfo 3.19.1-1.el7_1 Red Hat Enterprise Linux ComputeNode (v. 7) nss 3.19.1-3.el7_1, nss-util 3.19.1-1.el7_1, nss-tools 3.19.1-3.el7_1, nss-sysinit 3.19.1-3.el7_1 Red Hat Enterprise Linux ComputeNode Optional (v. 7) nss-devel 3.19.1-3.el7_1, nss-debuginfo 3.19.1-3.el7_1, nss-util-devel 3.19.1-1.el7_1, nss-pkcs11-devel 3.19.1-3.el7_1, nss-util-debuginfo 3.19.1-1.el7_1
    fixed: vendor fix RHSA-2015:1185
  • Red Hat Enterprise Linux Desktop (v. 5 client) nss 3.19.1-1.el5_11, nss-tools 3.19.1-1.el5_11
    fixed: vendor fix RHSA-2015:1664
  • Red Hat Enterprise Linux Desktop (v. 6) nss 3.19.1-3.el6_6, nss-util 3.19.1-1.el6_6, nss-tools 3.19.1-3.el6_6, nss-sysinit 3.19.1-3.el6_6 Red Hat Enterprise Linux Desktop Optional (v. 6) nss-devel 3.19.1-3.el6_6, nss-debuginfo 3.19.1-3.el6_6, nss-util-devel 3.19.1-1.el6_6, nss-pkcs11-devel 3.19.1-3.el6_6, nss-util-debuginfo 3.19.1-1.el6_6
    fixed: vendor fix RHSA-2015:1185
  • Red Hat Enterprise Linux Desktop Workstation (v. 5 client) nss 3.19.1-1.el5_11
    fixed: vendor fix RHSA-2015:1664
  • Red Hat Enterprise Linux HPC Node (v. 6) nss 3.19.1-3.el6_6, nss-util 3.19.1-1.el6_6, nss-tools 3.19.1-3.el6_6, nss-sysinit 3.19.1-3.el6_6 Red Hat Enterprise Linux HPC Node Optional (v. 6) nss-devel 3.19.1-3.el6_6, nss-debuginfo 3.19.1-3.el6_6, nss-util-devel 3.19.1-1.el6_6, nss-pkcs11-devel 3.19.1-3.el6_6, nss-util-debuginfo 3.19.1-1.el6_6 Red Hat Enterprise Linux Server (v. 6) nss 3.19.1-3.el6_6, nss-util 3.19.1-1.el6_6, nss-tools 3.19.1-3.el6_6, nss-sysinit 3.19.1-3.el6_6 Red Hat Enterprise Linux Server (v. 7) nss 3.19.1-3.el7_1, nss 3.19.1-3.ael7b_1, nss-util 3.19.1-1.el7_1, nss-tools 3.19.1-3.el7_1, nss-util 3.19.1-1.ael7b_1, nss-sysinit 3.19.1-3.el7_1, +2 more Red Hat Enterprise Linux Server Optional (v. 6) nss-debuginfo 3.19.1-3.el6_6, nss-pkcs11-devel 3.19.1-3.el6_6 Red Hat Enterprise Linux Server Optional (v. 7) nss-debuginfo 3.19.1-3.el7_1, nss-debuginfo 3.19.1-3.ael7b_1, nss-pkcs11-devel 3.19.1-3.el7_1, nss-pkcs11-devel 3.19.1-3.ael7b_1
    +4 more products
    Red Hat Enterprise Linux Workstation (v. 6) nss 3.19.1-3.el6_6, nss-util 3.19.1-1.el6_6, nss-tools 3.19.1-3.el6_6, nss-sysinit 3.19.1-3.el6_6 Red Hat Enterprise Linux Workstation (v. 7) nss 3.19.1-3.el7_1, nss-util 3.19.1-1.el7_1, nss-tools 3.19.1-3.el7_1, nss-sysinit 3.19.1-3.el7_1 Red Hat Enterprise Linux Workstation Optional (v. 6) nss-debuginfo 3.19.1-3.el6_6, nss-pkcs11-devel 3.19.1-3.el6_6 Red Hat Enterprise Linux Workstation Optional (v. 7) nss-debuginfo 3.19.1-3.el7_1, nss-pkcs11-devel 3.19.1-3.el7_1
    fixed: vendor fix RHSA-2015:1185
  • Red Hat Enterprise Linux 5 gnutls, openssl Red Hat Enterprise Linux 6 gnutls, openssl, gnutls-guile, gnutls-utils, openssl-perl Red Hat Enterprise Linux 7 gnutls, openssl, gnutls-c++, gnutls-dane, gnutls-utils, openssl-libs, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.83% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1086145 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.