Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
CVSS Details
- CVSS 3.1 Base Score: 8.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade firefoxUpgrade thunderbird | May 4, 2022 | Jun 24, 2021 |
| Alpine Linux | — | Upgrade firefox-esrUpgrade firefoxUpgrade thunderbirdUpgrade librewolf | Aug 22, 2024 | Jun 24, 2021 |
| Amazon Linux Ami 2 | — | Upgrade thunderbirdUpgrade thunderbird-debuginfo | May 26, 2021 | May 26, 2021 |
| Arch Linux | — | Upgrade to the latest version of Arch Linux | Jul 11, 2025 | Jun 24, 2021 |
| Centos_linux | — | Upgrade thunderbirdUpgrade thunderbird-debugsourceUpgrade firefoxUpgrade firefox-debugsourceUpgrade firefox-debuginfoUpgrade thunderbird-debuginfo | Jun 1, 2021 | Apr 26, 2021 |
| Debian | — | Upgrade thunderbirdUpgrade firefox-esr | Apr 23, 2021 | Apr 23, 2021 |
| Gentoo Linux | — | Upgrade mail-client/thunderbird.Upgrade www-client/firefox.Upgrade www-client/firefox-bin.Upgrade mail-client/thunderbird-bin. | May 3, 2021 | Apr 30, 2021 |
| Mfsa2021 15 | — | Upgrade to Mozilla Firefox ESR version 78.10 | Apr 20, 2021 | Apr 19, 2021 |
| Mfsa2021 16 | — | Upgrade to Mozilla Firefox version 88.0 | Apr 20, 2021 | Apr 19, 2021 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 78.10 | Apr 20, 2021 | Apr 19, 2021 |
| Oracle Solaris | — | Upgrade web/data/firefox-bookmarks to version 78.10.0-11.4.34.0.1.94.3 on Solaris 11.4Upgrade web/browser/firefox to version 78.10.0-11.4.34.0.1.94.3 on Solaris 11.4Upgrade mail/thunderbird to version 78.10.0-11.4.34.0.1.94.3 on Solaris 11.4 | Jun 16, 2021 | Jun 16, 2021 |
| Oracle_linux | — | Upgrade thunderbirdUpgrade firefox | Apr 27, 2021 | Apr 19, 2021 |
| Redhat_linux | — | Upgrade firefox-debugsourceUpgrade thunderbird-debugsourceUpgrade firefox-debuginfoNo solution existsUpgrade firefoxUpgrade thunderbird-debuginfoUpgrade thunderbird | Apr 27, 2021 | Apr 26, 2021 |
| Suse | — | Upgrade mozillafirefox-translations-commonUpgrade mozillafirefox-develUpgrade mozillathunderbirdUpgrade mozillathunderbird-translations-otherUpgrade mozillathunderbird-translations-commonUpgrade mozillafirefox-buildsymbolsUpgrade mozillafirefox-translations-otherUpgrade mozillafirefoxUpgrade mozillafirefox-branding-upstream | Apr 27, 2021 | Apr 23, 2021 |
| Ubuntu | — | Upgrade firefoxUpgrade thunderbird | Apr 27, 2021 | Apr 27, 2021 |
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