{"id":"CVE-2017-7764","url":"https://www.cyber-defence.io/tools/cve/CVE-2017-7764","generatedAt":"2026-10-28T19:47:07.552Z","title":"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.","description":"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.","published":"2018-06-11T21:29:08.000Z","lastModified":"2026-06-17T01:25:09.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-20"],"affected":["mozilla/firefox","mozilla/thunderbird","debian/debian linux"],"epss":{"score":0.01962,"percentile":0.8022,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.96%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/99057","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"http://www.securitytracker.com/id/1038689","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://access.redhat.com/errata/RHSA-2017:1440","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://access.redhat.com/errata/RHSA-2017:1561","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1364283","tags":["Exploit","Issue Tracking","Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.debian.org/security/2017/dsa-3881","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.debian.org/security/2017/dsa-3918","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-15/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-16/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-17/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"http://www.securityfocus.com/bid/99057","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1038689","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2017:1440","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2017:1561","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1364283","tags":["Exploit","Issue Tracking","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2017/dsa-3881","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2017/dsa-3918","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-15/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-16/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-17/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2017-7764","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}