Characters from the "Canadian Syllabics" unicode block can be mixed with characters from other unicode blocks in the addressbar instead of being rendered as their raw "punycode" form, allowing for domain name spoofing attacks through character confusion. The current Unicode standard allows characters from "Aspirational Use Scripts" such as Canadian Syllabics to be mixed with Latin characters in the "moderately restrictive" IDN profile. We have changed Firefox behavior to match the upcoming Unicode version 10.0 which removes this category and treats them as "Limited Use Scripts.". This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.
CVSS Details
- CVSS 3.1 Base Score: 5.3
- CVSS 3.0 Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade firefox-esr | Aug 30, 2017 | Jun 15, 2017 |
| Arch Linux | — | Upgrade to the latest version of Arch Linux | Jul 11, 2025 | Jun 11, 2018 |
| Centos_linux | — | Upgrade thunderbirdUpgrade thunderbird-debuginfoUpgrade firefox-debuginfoUpgrade firefox | Jun 16, 2017 | Jun 14, 2017 |
| Debian | — | Upgrade icedoveUpgrade firefox-esr | Jun 16, 2017 | Jun 14, 2017 |
| Freebsd | — | Upgrade linux-thunderbirdUpgrade firefox-esrUpgrade linux-firefoxUpgrade libxulUpgrade thunderbirdUpgrade linux-seamonkeyUpgrade firefoxUpgrade seamonkey | Jun 16, 2017 | Jun 13, 2017 |
| Gentoo Linux | — | Upgrade www-client/firefox.Upgrade www-client/firefox-bin. | Feb 20, 2018 | Feb 20, 2018 |
| Mfsa2017 15 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox version 54.0 | Jul 12, 2018 | Jun 11, 2018 |
| Mfsa2017 16 | — | Upgrade to the latest version of Mozilla FirefoxUpgrade to Mozilla Firefox ESR version 52.2 | Jun 14, 2017 | Jun 13, 2017 |
| Mozilla Thunderbird | — | Upgrade to Mozilla Thunderbird version 52.2Upgrade to the latest version of Mozilla Thunderbird | Jun 15, 2017 | Jun 14, 2017 |
| Oracle Solaris | — | Upgrade mail/thunderbird/plugin/thunderbird-lightning to version 52.2.0-0.175.3.22.0.3.0 on Solaris 11.3Upgrade web/browser/firefox to version 52.2.0-0.175.3.22.0.2.0 on Solaris 11.3Upgrade mail/thunderbird to version 52.2.0-0.175.3.22.0.3.0 on Solaris 11.3Upgrade web/data/firefox-bookmarks to version 52.2.0-0.175.3.22.0.2.0 on Solaris 11.3Upgrade web/browser/firefox/plugin/firefox-java to version 52.2.0-0.175.3.22.0.2.0 on Solaris 11.3 | Jul 19, 2017 | Jul 19, 2017 |
| Oracle_linux | — | Upgrade firefoxUpgrade thunderbird | Jun 15, 2017 | Jun 14, 2017 |
| Redhat_linux | — | Upgrade thunderbirdUpgrade firefox-debuginfoUpgrade firefoxUpgrade thunderbird-debuginfo | Jun 15, 2017 | Jun 14, 2017 |
| Suse | — | Upgrade MozillaFirefox-develUpgrade MozillaThunderbird-buildsymbolsUpgrade MozillaThunderbird-translations-commonUpgrade MozillaThunderbird-translations-otherUpgrade MozillaFirefox-translations-commonUpgrade libfreebl3Upgrade MozillaFirefox-translations-otherUpgrade MozillaThunderbirdUpgrade firefox-libffi4Upgrade libsoftokn3-32bitUpgrade MozillaFirefox-branding-SLEDUpgrade mozilla-nssUpgrade libsoftokn3Upgrade MozillaFirefox-translationsUpgrade MozillaFirefoxUpgrade mozilla-nss-32bitUpgrade mozilla-nss-x86Upgrade libsoftokn3-x86Upgrade MozillaThunderbird-develUpgrade mozilla-nss-develUpgrade libfreebl3-x86Upgrade mozilla-nss-toolsUpgrade mozillafirefox-branding-sleUpgrade firefox-libstdc++6Upgrade libfreebl3-32bit | Jun 19, 2017 | Jun 14, 2017 |
| Ubuntu | — | Upgrade firefoxUpgrade thunderbird | Jun 16, 2017 | Jun 14, 2017 |
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