CVE-2018-12395

Name: CVE-2018-12395
Creator: NVD / NIST
Published: 2019-02-28T18:29:00.743+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.85%

Last modified Jun 17, 2026

CVE-2018-12395 is a vulnerability of currently unknown severity. By rewriting the Host: request headers using the webRequest API, a WebExtension can bypass domain restrictions through domain fronting. This would allow access to domains that share a host that are otherwise restricted. EPSS estimates a 2.85% chance of exploitation in the next 30 days.

Description

By rewriting the Host: request headers using the webRequest API, a WebExtension can bypass domain restrictions through domain fronting. This would allow access to domains that share a host that are otherwise restricted. This vulnerability affects Firefox ESR < 60.3 and Firefox < 63.

Metrics

EPSS Probability

2.85%

84.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 63.0
Mozilla	Firefox Esr	< 60.3
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Canonical	Ubuntu Linux	14.04
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10
Redhat	Enterprise Linux Desktop	6.0
Redhat	Enterprise Linux Desktop	7.0
Redhat	Enterprise Linux Server	6.0
Redhat	Enterprise Linux Server	7.0
Redhat	Enterprise Linux Server Eus	7.5
Redhat	Enterprise Linux Workstation	6.0
Redhat	Enterprise Linux Workstation	7.0

References

http://www.securityfocus.com/bid/105718Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041944Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2018:3005Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3006Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1467523Issue Tracking, Permissions Required, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2018/11/msg00008.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/201811-04Third Party Advisory
https://usn.ubuntu.com/3801-1/Third Party Advisory
https://www.debian.org/security/2018/dsa-4324Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2018-26/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2018-27/Vendor Advisory
http://www.securityfocus.com/bid/105718Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041944Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2018:3005Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3006Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1467523Issue Tracking, Permissions Required, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2018/11/msg00008.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/201811-04Third Party Advisory
https://usn.ubuntu.com/3801-1/Third Party Advisory
https://www.debian.org/security/2018/dsa-4324Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2018-26/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2018-27/Vendor Advisory

Timeline

Published: Feb 28, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-12395?

How severe is CVE-2018-12395?

Severity scoring for CVE-2018-12395 is pending analysis. The EPSS model estimates a 2.85% probability of exploitation in the next 30 days.

How do I fix CVE-2018-12395?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-12395?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST