CVE-2017-7764
Characters from the "Canadian Syllabics" unicode block can be mixed with characters from other unicode blocks in the addressbar instead of…
- Published
- Updated
- Reserved
- Assigned by
- mozilla
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.
Timeline
ID reserved
By mozilla
- 14 months later
· 14 months later
Published
- 6 years later
· 6 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 2.0% · top 20% of all CVEs (8 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
- Domain spoofing with combination of Canadian Syllabics and other unicode blocks
- CWE-20 (opens in a new tab)All about CWE-20 and its CVEs
Affected products
- affected unspecified – < 54
- affected unspecified – < 52.2
- affected unspecified – < 52.2
References (11)
- 99057 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts (opens in a new tab)x_refsource_MISCx_transferred
- https://www.mozilla.org/security/advisories/mfsa2017-15/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- DSA-3918 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- 1038689 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- https://bugzilla.mozilla.org/show_bug.cgi?id=1364283 (opens in a new tab)x_refsource_CONFIRMx_transferred
- DSA-3881 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- RHSA-2017:1440 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2017:1561 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- https://www.mozilla.org/security/advisories/mfsa2017-17/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://www.mozilla.org/security/advisories/mfsa2017-16/ (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2017-7764)Record last updated .