CVE-2018-12395

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.

7.5
CVSS
Severity: High
CVSS 3.0 •
CVSS 2.0 •
EPSS 1.89% Top 20%
Vendor Advisory debian.org Vendor Advisory gentoo.org Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory ubuntu.com Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Firefox ESR
Affected: Mozilla Firefox
Published at:
Updated at:

References

Link Tags
https://www.debian.org/security/2018/dsa-4324 third party advisory vendor advisory
https://www.mozilla.org/security/advisories/mfsa2018-26/ vendor advisory
https://security.gentoo.org/glsa/201811-04 third party advisory vendor advisory
https://www.mozilla.org/security/advisories/mfsa2018-27/ vendor advisory
https://access.redhat.com/errata/RHSA-2018:3005 third party advisory vendor advisory
http://www.securityfocus.com/bid/105718 third party advisory vdb entry
https://access.redhat.com/errata/RHSA-2018:3006 third party advisory vendor advisory
https://usn.ubuntu.com/3801-1/ third party advisory vendor advisory
https://lists.debian.org/debian-lts-announce/2018/11/msg00008.html third party advisory mailing list
http://www.securitytracker.com/id/1041944 third party advisory vdb entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1467523 vendor advisory issue tracking permissions required

Frequently Asked Questions

What is the severity of CVE-2018-12395?
CVE-2018-12395 has been scored as a high severity vulnerability.
How to fix CVE-2018-12395?
To fix CVE-2018-12395, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2018-12395 being actively exploited in the wild?
It is possible that CVE-2018-12395 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2018-12395?
CVE-2018-12395 affects Mozilla Firefox ESR, Mozilla Firefox.
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