CVE-2017-7764

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.

• CWE-20

• http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
• http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
• http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_ScriptsThird Party Advisory
• https://access.redhat.com/errata/RHSA-2017:1440Third Party Advisory
• https://access.redhat.com/errata/RHSA-2017:1561Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1364283Exploit, Issue Tracking, Vendor Advisory
• https://www.debian.org/security/2017/dsa-3881Third Party Advisory
• https://www.debian.org/security/2017/dsa-3918Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-17/Vendor Advisory
• http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
• http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
• http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_ScriptsThird Party Advisory
• https://access.redhat.com/errata/RHSA-2017:1440Third Party Advisory
• https://access.redhat.com/errata/RHSA-2017:1561Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1364283Exploit, Issue Tracking, Vendor Advisory
• https://www.debian.org/security/2017/dsa-3881Third Party Advisory
• https://www.debian.org/security/2017/dsa-3918Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2017-17/Vendor Advisory

Published

Jun 11, 2018

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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