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Fencer Vulns
medium 5.3

CVE-2019-11727 json

A vulnerability exists where it possible to force Network Security Services (NSS) to sign CertificateVerify with PKCS#1 v1.5 signatures whe…

published 2019-07-23 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-3397

cvss
5.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

A vulnerability exists where it possible to force Network Security Services (NSS) to sign CertificateVerify with PKCS#1 v1.5 signatures when those are the only ones advertised by server in CertificateRequest in TLS 1.3. PKCS#1 v1.5 signatures should not be used for TLS 1.3 messages. This vulnerability affects Firefox < 68.

Patch / fix

  • Mozilla Firefox 68
  • nss Debian 14, Debian 13, Debian 12 2:3.45-1

debian advisories DEBIAN-CVE-2019-11727

  • firefox Ubuntu 16.04 LTS 68.0+build3-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 68.0+build3-0ubuntu0.18.04.1
  • thunderbird Ubuntu 16.04 LTS 1:68.7.0+build1-0ubuntu0.16.04.2

ubuntu advisories UBUNTU-CVE-2019-11727

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 7 3.53.1-3.el7_9
  • nspr RHEL 7 4.25.0-2.el7_9
  • nss-util RHEL 7 3.53.1-1.el7_9
  • nss-tools RHEL 7 3.53.1-3.el7_9
  • nss-softokn RHEL 7 3.53.1-6.el7_9
  • nss-sysinit RHEL 7 3.53.1-3.el7_9
  • nss-softokn-freebl RHEL 7 3.53.1-6.el7_9
  • nss RHEL 8 3.44.0-7.el8_0

red hat advisories RHSA-2020:4076RHSA-2019:1951

  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 68.1.0-109.89.1
  • MozillaFirefox-branding-SLE SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +16 more 68-32.8.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68.1.0-3.54.2
  • MozillaFirefox-branding-SLE SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68-4.8.5
  • MozillaThunderbird SLE Workstation Extension 15 SP1, SLE Workstation Extension 15 68.1.1-3.51.1
  • mozilla-nss SLES 11 SP4-LTSS 3.53.1-38.23.1
  • mozilla-nspr SLES 11 SP4-LTSS 4.25-29.12.2
  • firefox-atk SLES 11 SP4-LTSS 2.26.1-2.8.4

suse advisories SUSE-SU-2020:14418-1SUSE-SU-2019:14246-1SUSE-SU-2019:2620-1SUSE-SU-2019:2545-1SUSE-SU-2019:2515-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • mozilla-nss openSUSE Tumbleweed 3.69.1-1.2
  • MozillaFirefox openSUSE Leap 15.0 68.1.0-lp150.3.66.1
  • MozillaFirefox openSUSE Leap 15.1 68.1.0-lp151.2.14.1
  • MozillaThunderbird openSUSE Leap 15.1 68.1.1-lp151.2.13.1
  • enigmail openSUSE Leap 15.1 2.1.2-lp151.2.6.1
  • MozillaThunderbird openSUSE Leap 15.0 68.1.1-lp150.3.51.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:11058-1openSUSE-SU-2019:2260-1openSUSE-SU-2019:2251-1openSUSE-SU-2019:2249-1

  • firefox Arch Linux 68.0-1

arch linux advisories AVG-1002

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-2019-11727 updated cvss 3.4

nss: PKCS#1 v1.5 signatures can be used for TLS 1.3

  • Red Hat Enterprise Linux 5 nss Red Hat Enterprise Linux 6 nss, nss-tools, nss-sysinit
    affected: no fix planned “Out of support scope”
  • Red Hat OpenShift Do 1 openshiftdo/odo-init-image-rhel7 1.1.3-2
    fixed: vendor fix RHSA-2021:0949
  • Red Hat Enterprise Linux AppStream (v. 8) nss 3.44.0-7.el8_0, nspr 4.21.0-2.el8_0, nss-util 3.44.0-7.el8_0, nss-tools 3.44.0-7.el8_0, nss-softokn 3.44.0-7.el8_0, nss-sysinit 3.44.0-7.el8_0, +1 more
    fixed: vendor fix RHSA-2019:1951
  • Red Hat Enterprise Linux Client (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more Red Hat Enterprise Linux Client Optional (v. 7) nss-devel 3.53.1-3.el7_9, nspr-devel 4.25.0-2.el7_9, nss-debuginfo 3.53.1-3.el7_9, nspr-debuginfo 4.25.0-2.el7_9, nss-util-devel 3.53.1-1.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9, +4 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) nss-devel 3.53.1-3.el7_9, nspr-devel 4.25.0-2.el7_9, nss-debuginfo 3.53.1-3.el7_9, nspr-debuginfo 4.25.0-2.el7_9, nss-util-devel 3.53.1-1.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9, +4 more Red Hat Enterprise Linux Server (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more Red Hat Enterprise Linux Server Optional (v. 7) nss-debuginfo 3.53.1-3.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9 Red Hat Enterprise Linux Workstation (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more
    +1 more products
    Red Hat Enterprise Linux Workstation Optional (v. 7) nss-debuginfo 3.53.1-3.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9
    fixed: vendor fix RHSA-2020:4076

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

1.81% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • Mozilla Firefox

Classification

Weakness
  • CWE-295 Improper Certificate Validation

References

Sources

Fencer Vulns 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.