CVE-2019-11727

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-07-23 · updated 2026-06-17
Weakness: CWE-295

Description

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.

Affected products

Mozilla Firefox: before 68.0 — fixed in 68.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 68.0. Check the vendor advisory for mitigations.

References

http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00006.html
https://access.redhat.com/errata/RHSA-2019:1951
https://bugzilla.mozilla.org/show_bug.cgi?id=1552208
https://security.gentoo.org/glsa/201908-12
https://www.mozilla.org/security/advisories/mfsa2019-21/
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html

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