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 | — | alpine-linux-upgrade-firefox-esr | Aug 30, 2017 | Jun 15, 2017 |
| Arch Linux | arch-linux-upgrade-latest | Jul 11, 2025 | Jun 11, 2018 | |
| Centos_linux | — | centos-upgrade-firefoxcentos-upgrade-firefox-debuginfocentos-upgrade-thunderbirdcentos-upgrade-thunderbird-debuginfo | Jun 16, 2017 | Jun 14, 2017 |
| Debian | debian-upgrade-firefox-esrdebian-upgrade-icedove | Jun 16, 2017 | Jun 14, 2017 | |
| Freebsd | freebsd-upgrade-package-firefoxfreebsd-upgrade-package-seamonkeyfreebsd-upgrade-package-linux-seamonkeyfreebsd-upgrade-package-firefox-esrfreebsd-upgrade-package-linux-firefoxfreebsd-upgrade-package-libxulfreebsd-upgrade-package-thunderbirdfreebsd-upgrade-package-linux-thunderbird | Jun 16, 2017 | Jun 13, 2017 | |
| Gentoo Linux | gentoo-linux-upgrade-www-client-firefoxgentoo-linux-upgrade-www-client-firefox-bin | Feb 20, 2018 | Feb 20, 2018 | |
| Mfsa2017 15 | mozilla-firefox-upgrade-54_0 | Jul 12, 2018 | Jun 11, 2018 | |
| Mfsa2017 16 | mozilla-firefox-esr-upgrade-52_2 | Jun 14, 2017 | Jun 13, 2017 | |
| Mozilla Thunderbird | mozilla-thunderbird-upgrade-52_2 | Jun 15, 2017 | Jun 14, 2017 | |
| Oracle Solaris | oracle-solaris-11-3-upgrade-mail-thunderbird-52-2-0-0-175-3-22-0-3-0oracle-solaris-11-3-upgrade-mail-thunderbird-plugin-thunderbird-lightning-52-2-0-0-175-3-22-0-3-0oracle-solaris-11-3-upgrade-web-browser-firefox-52-2-0-0-175-3-22-0-2-0oracle-solaris-11-3-upgrade-web-browser-firefox-plugin-firefox-java-52-2-0-0-175-3-22-0-2-0oracle-solaris-11-3-upgrade-web-data-firefox-bookmarks-52-2-0-0-175-3-22-0-2-0 | Jul 19, 2017 | Jul 19, 2017 | |
| Oracle_linux | — | oracle-linux-upgrade-firefoxoracle-linux-upgrade-thunderbird | Jun 15, 2017 | Jun 14, 2017 |
| Redhat_linux | — | redhat-upgrade-firefoxredhat-upgrade-firefox-debuginforedhat-upgrade-thunderbirdredhat-upgrade-thunderbird-debuginfo | Jun 15, 2017 | Jun 14, 2017 |
| Suse | — | suse-upgrade-firefox-libffi4suse-upgrade-firefox-libstdc-6suse-upgrade-libfreebl3suse-upgrade-libfreebl3-32bitsuse-upgrade-libfreebl3-x86suse-upgrade-libsoftokn3suse-upgrade-libsoftokn3-32bitsuse-upgrade-libsoftokn3-x86suse-upgrade-mozilla-nsssuse-upgrade-mozilla-nss-32bitsuse-upgrade-mozilla-nss-develsuse-upgrade-mozilla-nss-toolssuse-upgrade-mozilla-nss-x86suse-upgrade-mozillafirefoxsuse-upgrade-mozillafirefox-branding-slesuse-upgrade-mozillafirefox-branding-sledsuse-upgrade-mozillafirefox-develsuse-upgrade-mozillafirefox-translationssuse-upgrade-mozillafirefox-translations-commonsuse-upgrade-mozillafirefox-translations-othersuse-upgrade-mozillathunderbirdsuse-upgrade-mozillathunderbird-buildsymbolssuse-upgrade-mozillathunderbird-develsuse-upgrade-mozillathunderbird-translations-commonsuse-upgrade-mozillathunderbird-translations-other | Jun 19, 2017 | Jun 14, 2017 |
| Ubuntu | ubuntu-upgrade-firefoxubuntu-upgrade-thunderbird | Jun 16, 2017 | Jun 14, 2017 |
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