Description
By holding a reference to the eval() function from an about:blank window, a malicious webpage could have gained access to the InstallTrigger object which would allow them to prompt the user to install an extension. Combined with user confusion, this could result in an unintended or malicious extension being installed. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox ESR < 68.12, Firefox ESR < 78.2, and Firefox for Android < 80.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 80 | 80 |
| Mozilla | Thunderbird | unspecified – < 78.2, unspecified – < 68.12 | 78.2 |
| Mozilla | Firefox ESR | unspecified – < 68.12, unspecified – < 78.2 | 68.12 |
| Mozilla | Firefox for Android | unspecified – < 80 | 80 |
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 | 68.12.0esr-1 | — |
| Debian 14 | thunderbird | 1:68.12.0-1 | — |
| Debian 13 | firefox-esr | 68.12.0esr-1 | — |
| Debian 13 | thunderbird | 1:68.12.0-1 | — |
| Debian 12 | firefox-esr | 68.12.0esr-1 | — |
| Debian 12 | thunderbird | 1:68.12.0-1 | — |
| Debian 10 | firefox-esr | 68.12.0esr-1~deb10u1 | DSA-4749-1 |
| Debian 10 | thunderbird | 1:68.12.0-1~deb10u1 | DSA-4754-1 |
| Debian 9 | firefox-esr | 68.12.0esr-1~deb9u1 | DLA-2346-1 |
| Debian 9 | thunderbird | 1:68.12.0-1~deb9u1 | DLA-2360-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | firefox | 80.0+build2-0ubuntu0.20.04.1 | USN-4474-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | thunderbird | 1:78.7.1+build1-0ubuntu0.20.04.1 | — |
| Ubuntu 18.04 LTS | firefox | 80.0+build2-0ubuntu0.18.04.1 | USN-4474-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:78.8.1+build1-0ubuntu0.18.04.1 | — |
| Ubuntu 16.04 LTS | firefox | 80.0+build2-0ubuntu0.16.04.1 | USN-4474-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | firefox | 78.2.0-2.el8_2 | RHSA-2020:3557 |
| RHEL 8 | thunderbird | 68.12.0-1.el8_2 | RHSA-2020:3634 |
| RHEL 7 | firefox +1 | 68.12.0-1.el7_8 | RHSA-2020:3631, RHSA-2020:3556 |
| RHEL 6 | firefox +1 | 68.12.0-1.el6_10 | RHSA-2020:3643, RHSA-2020:3558 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | firefox | 78.2.0-3.el8_1 | RHSA-2020:3559 |
| RHEL 8.1 EUS | thunderbird | 68.12.0-1.el8_1 | RHSA-2020:3632 |
| RHEL 8.0 E4S | firefox | 78.2.0-3.el8_0 | RHSA-2020:3555 |
| RHEL 8.0 E4S | thunderbird | 68.12.0-1.el8_0 | RHSA-2020:3633 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaFirefox | 78.3.0-8.6.1 | SUSE-SU-2020:2749-1 |
| SLES 15 SP2 | MozillaThunderbird | 68.12.0-3.94.1 | SUSE-SU-2020:2552-1 |
| SLES 15 SP1 | MozillaFirefox | 78.2.0-3.105.1 | SUSE-SU-2020:2563-1 |
| SLES 15 SP1 | MozillaThunderbird | 68.12.0-3.94.1 | SUSE-SU-2020:2552-1 |
| SLES 12 SP5 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES 12 SP4 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES 12 SP3 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES 11 SP4 | MozillaFirefox | 78.2.0-78.90.2 | SUSE-SU-2020:14489-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox | 78.2.0-112.19.2 | SUSE-SU-2020:2544-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.2.0-lp152.2.18.1 | openSUSE-SU-2020:1391-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 68.12.0-lp152.2.10.1 | openSUSE-SU-2020:1392-1 |
| openSUSE Leap 15.1 | MozillaFirefox | 78.2.0-lp151.2.65.1 | openSUSE-SU-2020:1384-1 |
| openSUSE Leap 15.1 | MozillaThunderbird | 68.12.0-lp151.2.50.1 | openSUSE-SU-2020:1383-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 80.0-r0 | — |
| Alpine v3.23 | firefox +1 | 80.0-r0 | — |
| Alpine v3.23 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.22 | firefox +1 | 80.0-r0 | — |
| Alpine v3.22 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.21 | firefox +1 | 80.0-r0 | — |
| Alpine v3.21 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.20 | firefox | 80.0-r0 | — |
| Alpine v3.20 | firefox-esr | 78.2.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 80.0-r0 | — |
| Alpine v3.19 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.18 | firefox | 80.0-r0 | — |
| Alpine v3.18 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.17 | firefox | 80.0-r0 | — |
| Alpine v3.17 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.16 | firefox | 80.0-r0 | — |
| Alpine v3.16 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.15 | firefox | 80.0-r0 | — |
| Alpine v3.15 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.14 | firefox | 80.0-r0 | — |
| Alpine v3.14 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.13 | firefox | 80.0-r0 | — |
| Alpine v3.13 | firefox-esr | 78.2.0-r0 | — |
| Alpine v3.12 | firefox | 80.0-r0 | — |
| Alpine v3.12 | firefox-esr | 78.2.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 68.12.0-1.amzn2 | ALAS2-2020-1496 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | firefox | 78.2.0-2.0.1.el8_2 | ELSA-2020-3557 |
| Oracle Linux 8 | thunderbird | 68.12.0-1.0.1.el8_2 | ELSA-2020-3634 |
| Oracle Linux 7 | firefox | 68.12.0-1.0.3.el7_8 | ELSA-2020-3556 |
| Oracle Linux 7 | thunderbird | 68.12.0-1.0.1.el7_8 | ELSA-2020-3631 |
Advisories 32
- RHSA-2020:3631 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3643 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3558 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:3556 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4474-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4754-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4749-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2346-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2360-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:2552-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2544-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14489-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1384-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2563-1 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-2020:2749-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1391-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1383-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1392-1 Security update for MozillaThunderbird 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
- RHSA-2020:3557 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 28, 2026
- RHSA-2020:3559 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- RHSA-2020:3555 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- RHSA-2020:3634 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2020:3633 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2020:3632 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2020-1496 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 30, 2020
- ELSA-2020-3631 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Sep 17, 2020
- ELSA-2020-3634 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Sep 8, 2020
- ELSA-2020-3556 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Sep 8, 2020
- ELSA-2020-3557 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 28, 2020
References
- https://www.mozilla.org/security/advisories/mfsa2020-39/
- https://www.mozilla.org/security/advisories/mfsa2020-41/
- https://www.mozilla.org/security/advisories/mfsa2020-36/
- https://www.mozilla.org/security/advisories/mfsa2020-38/
- https://www.mozilla.org/security/advisories/mfsa2020-40/
- https://www.mozilla.org/security/advisories/mfsa2020-37/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1658214