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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 60.3 | 60.3 |
| Mozilla | Firefox | unspecified – < 63 | 63 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firefox-esr | 60.3.0esr-1 | — |
| Debian 13 | firefox-esr | 60.3.0esr-1 | — |
| Debian 12 | firefox-esr | 60.3.0esr-1 | — |
| Debian 9 | firefox-esr | 60.3.0esr-1~deb9u1 | DSA-4324-1 |
| Debian 8 | firefox-esr | 60.3.0esr-1~deb8u1 | DLA-1571-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 63.0+build2-0ubuntu0.18.04.2 | USN-3801-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 16.04 LTS | firefox | 63.0+build2-0ubuntu0.16.04.2 | USN-3801-1 |
| Ubuntu 14.04 LTS | firefox | 63.0+build2-0ubuntu0.14.04.2 | USN-3801-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox | 60.3.0-1.el7_5 | RHSA-2018:3005 |
| RHEL 6 | firefox | 60.3.0-1.el6 | RHSA-2018:3006 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | MozillaFirefox | 60.3.0-3.17.1 | SUSE-SU-2018:3656-1 |
| SLES 12 SP4 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-2 |
| SLES 12 SP3 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SLES 12 SP2 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SLES 12 SP1 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-2 |
| SLES for SAP 12 SP3 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-3 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
| SUSE Enterprise Storage 4 | MozillaFirefox | 60.3.0-109.50.2 | SUSE-SU-2018:3749-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | firefox | 60.3.0-1.0.1.el7_5 | ELSA-2018-3005 |
Advisories 12
- RHSA-2018:3005 Red Hat Security Advisory: firefox security and bug fix update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- RHSA-2018:3006 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 27, 2026
- USN-3801-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4324-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1571-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:3656-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3749-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3749-3 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3749-2 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 2, 2025
- ELSA-2018-3005 Critical: firefox security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 24, 2018
References
- DSA-4324 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2018-26/
- GLSA-201811-04 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2018-27/
- RHSA-2018:3005 vendor-advisory
- 105718 vdb-entry
- RHSA-2018:3006 vendor-advisory
- USN-3801-1 vendor-advisory
- [debian-lts-announce] 20181107 [SECURITY] [DLA 1571-1] firefox-esr security update mailing-list
- 1041944 vdb-entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1467523