CVE-2018-12395: High severity Mozilla Firefox vulnerability

Published Oct 23, 2018
·
Updated

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.

External Reference:

https://www.mozilla.org/en-US/security/advisories/mfsa2018-27/#CVE-2018-12395

Other sources

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.

Mozilla

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.

Launchpad

Affected Software

19 affected componentsFixes available
Mozilla Firefox<63
63
Mozilla Firefox ESR<60.3
60.3
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
debian/firefox
149.0.2-1
debian/firefox-esr
115.14.0esr-1~deb11u1140.9.1esr-1~deb11u1128.14.0esr-1~deb12u1140.9.1esr-1~deb12u1140.8.0esr-1~deb13u1140.9.1esr-1~deb13u1140.9.1esr-1

Event History

Oct 23, 2018
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Red Hat·10:07 PM
DescriptionSeverityAffected Software
Feb 28, 2019
CVE Published
via MITRE·06:00 PM
Data Sourced
via MITRE·06:00 PM
DescriptionWeakness
Jan 11, 2024
Data Sourced
via Launchpad·10:49 PM
Description
Dec 11, 2025
Data Sourced
via Ubuntu·06:26 PM
RemedyDescriptionSeverityAffected Software
Apr 15, 2026
Data Sourced
via Debian·05:02 PM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the vulnerability ID for this vulnerability?

The vulnerability ID for this vulnerability is CVE-2018-12395.

2

How does this vulnerability impact Firefox ESR?

This vulnerability affects Firefox ESR versions prior to 60.3.

3

How does this vulnerability impact Firefox?

This vulnerability affects Firefox versions prior to 63.0.

4

How does this vulnerability impact Debian Debian Linux?

This vulnerability affects Debian Debian Linux version 8.0 and 9.0.

5

How does this vulnerability impact Canonical Ubuntu Linux?

This vulnerability affects Canonical Ubuntu Linux versions 14.04, 16.04, 18.04, and 18.10.

6

How does this vulnerability impact Redhat Enterprise Linux Desktop?

This vulnerability affects Redhat Enterprise Linux Desktop versions 6.0 and 7.0.

7

How does this vulnerability impact Redhat Enterprise Linux Server?

This vulnerability affects Redhat Enterprise Linux Server versions 6.0, 7.0, and 7.5.

8

How does this vulnerability impact Redhat Enterprise Linux Workstation?

This vulnerability affects Redhat Enterprise Linux Workstation versions 6.0 and 7.0.

9

How can I fix this vulnerability?

To fix this vulnerability, upgrade to Firefox ESR 60.3 or later and Firefox 63.0 or later.

10

Are there any references for this vulnerability?

Yes, you can find references for this vulnerability at the following links: [Bugzilla](https://bugzilla.mozilla.org/show_bug.cgi?id=1467523), [Mozilla security advisories](https://www.mozilla.org/en-US/security/advisories/mfsa2018-27/), [CVE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12395).

11

What is the severity of CVE-2018-12395?

The severity of CVE-2018-12395 is high, with a severity value of 7.5.

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