It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade firefoxUpgrade thunderbirdUpgrade firefox-esrUpgrade librewolf | Jan 4, 2021 | Dec 9, 2020 |
| Amazon Linux Ami 2 | — | Upgrade thunderbirdUpgrade thunderbird-debuginfo | Jan 8, 2021 | Dec 9, 2020 |
| Arch Linux | — | Upgrade to the latest version of Arch Linux | Jul 11, 2025 | Dec 9, 2020 |
| Centos_linux | — | Upgrade thunderbirdUpgrade firefoxUpgrade thunderbird-debugsourceUpgrade thunderbird-debuginfoUpgrade firefox-debugsourceUpgrade firefox-debuginfo | Dec 1, 2020 | Nov 30, 2020 |
| Debian | — | Upgrade thunderbirdUpgrade firefox-esr | Nov 20, 2020 | Nov 20, 2020 |
| Gentoo Linux | — | Upgrade www-client/firefox-bin.Upgrade mail-client/thunderbird.Upgrade www-client/firefox.Upgrade mail-client/thunderbird-bin. | Dec 7, 2020 | Dec 7, 2020 |
| Mfsa2020 50 | — | Upgrade to Mozilla Firefox version 83.0Upgrade to the latest version of Mozilla Firefox | Nov 18, 2020 | Nov 17, 2020 |
| Mfsa2020 51 | — | Upgrade to Mozilla Firefox ESR version 78.5Upgrade to the latest version of Mozilla Firefox | Nov 18, 2020 | Nov 17, 2020 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 78.5Upgrade to the latest version of Mozilla Thunderbird | Nov 18, 2020 | Nov 17, 2020 |
| Oracle Solaris | — | Upgrade mail/thunderbird to version 78.5.0-11.4.28.0.1.82.2 on Solaris 11.4Upgrade web/browser/firefox to version 78.5.0-11.4.28.0.1.82.2 on Solaris 11.4Upgrade web/data/firefox-bookmarks to version 78.5.0-11.4.28.0.1.82.2 on Solaris 11.4 | Jan 19, 2021 | Dec 9, 2020 |
| Oracle_linux | — | Upgrade thunderbirdUpgrade firefox | Dec 1, 2020 | Nov 17, 2020 |
| Redhat_linux | — | Upgrade firefox-debuginfoNo solution existsUpgrade thunderbird-debugsourceUpgrade firefox-debugsourceUpgrade thunderbird-debuginfoUpgrade thunderbirdUpgrade firefox | Dec 1, 2020 | Nov 30, 2020 |
| Suse | — | Upgrade mozillafirefox-branding-upstreamUpgrade mozillafirefox-buildsymbolsUpgrade MozillaFirefoxUpgrade MozillaThunderbird-translations-commonUpgrade MozillaFirefox-translations-commonUpgrade MozillaThunderbirdUpgrade MozillaFirefox-develUpgrade MozillaFirefox-translations-otherUpgrade MozillaThunderbird-translations-other | Nov 25, 2020 | Nov 18, 2020 |
| Ubuntu | — | Upgrade firefoxUpgrade thunderbird | Nov 19, 2020 | Nov 18, 2020 |
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