Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters - enabling the use of entities to mask the actual characters of interest from filters. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
CVSS Details
- CVSS 3.1 Base Score: 6.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade firefoxUpgrade librewolfUpgrade firefox-esr | Aug 22, 2024 | Jan 8, 2020 |
| Amazon Linux Ami 2 | — | Upgrade thunderbirdUpgrade thunderbird-debuginfo | Apr 27, 2020 | Jan 8, 2020 |
| Arch Linux | — | Upgrade to the latest version of Arch Linux | Jul 11, 2025 | Jan 8, 2020 |
| Centos_linux | — | Upgrade firefox-debugsourceUpgrade thunderbird-debugsourceUpgrade firefoxUpgrade firefox-debuginfoUpgrade thunderbirdUpgrade thunderbird-debuginfo | Oct 25, 2019 | Oct 23, 2019 |
| Debian | — | Upgrade firefox-esrUpgrade thunderbird | Oct 28, 2019 | Oct 28, 2019 |
| Gentoo Linux | — | Upgrade mail-client/thunderbird.Upgrade mail-client/thunderbird-bin. | Mar 16, 2020 | Jan 8, 2020 |
| Mfsa2019 33 | — | Upgrade to Mozilla Firefox ESR version 68.2 | Oct 23, 2019 | Oct 22, 2019 |
| Mfsa2019 34 | — | Upgrade to Mozilla Firefox version 70.0 | Oct 23, 2019 | Oct 22, 2019 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 68.2 | Oct 25, 2019 | Oct 22, 2019 |
| Oracle Solaris | — | Upgrade web/browser/firefox to version 68.2.0-11.4.15.0.1.4.0 on Solaris 11.4Upgrade mail/thunderbird to version 68.2.0-11.4.15.0.1.4.0 on Solaris 11.4Upgrade web/data/firefox-bookmarks to version 68.2.0-11.4.15.0.1.4.0 on Solaris 11.4Upgrade mail/thunderbird/plugin/thunderbird-lightning to version 68.2.0-11.4.15.0.1.4.0 on Solaris 11.4 | Nov 20, 2019 | Nov 20, 2019 |
| Oracle_linux | — | Upgrade thunderbirdUpgrade firefox | Oct 30, 2019 | Oct 22, 2019 |
| Redhat_linux | — | Upgrade thunderbird-debugsourceUpgrade firefox-debuginfoUpgrade firefoxUpgrade firefox-debugsourceNo solution existsUpgrade thunderbird-debuginfoUpgrade thunderbird | Oct 25, 2019 | Oct 23, 2019 |
| Suse | — | Upgrade firefox-gio-branding-upstreamUpgrade firefox-libatk-1_0-0Upgrade firefox-glib2-langUpgrade firefox-gtk3-immodule-amharicUpgrade libfirefox-gobject-2_0-0Upgrade firefox-gdk-pixbuf-thumbnailerUpgrade firefox-atk-langUpgrade mozilla-nsprUpgrade mozillafirefox-branding-sleUpgrade firefox-gtk3-immodules-tigrignaUpgrade mozilla-nss-toolsUpgrade firefox-gdk-pixbuf-langUpgrade firefox-libharfbuzz0Upgrade mozilla-nss-develUpgrade firefox-libffi4Upgrade mozillafirefox-translations-otherUpgrade mozilla-nspr-32bitUpgrade firefox-gtk3-immodule-thaiUpgrade mozilla-nspr-develUpgrade mozillathunderbird-translations-otherUpgrade firefox-libgdk_pixbuf-2_0-0Upgrade firefox-gtk3-immodule-multipressUpgrade libfreebl3-32bitUpgrade firefox-gtk3-dataUpgrade firefox-gtk3-langUpgrade libsoftokn3-32bitUpgrade firefox-gtk3-immodule-vietnameseUpgrade mozillathunderbirdUpgrade mozillafirefox-develUpgrade MozillaFirefox-branding-openSUSEUpgrade firefox-gtk3-immodule-inuktitutUpgrade libfirefox-gthread-2_0-0Upgrade mozilla-nss-32bitUpgrade libfirefox-gmodule-2_0-0Upgrade mozillafirefox-branding-upstreamUpgrade libfirefox-gio-2_0-0Upgrade mozillathunderbird-translations-commonUpgrade firefox-gdk-pixbuf-query-loadersUpgrade firefox-esr-branding-openSUSEUpgrade mozillafirefox-buildsymbolsUpgrade mozillafirefox-branding-sledUpgrade firefox-libpango-1_0-0Upgrade firefox-libffi7Upgrade libsoftokn3Upgrade mozillafirefox-translations-commonUpgrade mozilla-nss-certsUpgrade firefox-gtk3-branding-upstreamUpgrade libfirefox-glib-2_0-0Upgrade firefox-libgtk-3-0Upgrade firefox-libcairo2Upgrade firefox-gtk3-toolsUpgrade firefox-gtk3-immodule-ximUpgrade mozilla-nss-certs-32bitUpgrade mozilla-nssUpgrade firefox-glib2-toolsUpgrade libfreebl3Upgrade mozillafirefoxUpgrade firefox-libcairo-gobject2 | Nov 1, 2019 | Oct 23, 2019 |
| Ubuntu | — | Upgrade firefoxUpgrade thunderbird | Oct 24, 2019 | Oct 23, 2019 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub