Mozilla: Domain spoofing with combination of Canadian Syllabics and other unicode blocks (MFSA 2017-16)
Published Jun 11, 2018
5.3
MEDIUMCVSS 3.0
EPSS 2.00%
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.
Affected products
-
- Version unspecifiedStatusaffectedConstraints<54
- Version
-
- Version unspecifiedStatusaffectedConstraints<52.2
- Version
-
- Version unspecifiedStatusaffectedConstraints<52.2
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Mozilla | Firefox | n/a |
| ||||||
| Mozilla | Firefox ESR | n/a |
| ||||||
| Mozilla | Thunderbird | n/a |
|
Configuration 1
Configuration 2
- 8.0
- 9.0
No data.
Red Hat Enterprise Linux 6
firefox-0:52.2.0-1.el6_9
Fixed · RHSA-2017:1440
Red Hat Enterprise Linux 6
thunderbird-0:52.2.0-1.el6_9
Fixed · RHSA-2017:1561
Red Hat Enterprise Linux 7
firefox-0:52.2.0-1.el7_3
Fixed · RHSA-2017:1440
Red Hat Enterprise Linux 7
thunderbird-0:52.2.0-1.el7_3
Fixed · RHSA-2017:1561
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | firefox-0:52.2.0-1.el6_9 | Fixed | RHSA-2017:1440 |
| Red Hat Enterprise Linux 6 | thunderbird-0:52.2.0-1.el6_9 | Fixed | RHSA-2017:1561 |
| Red Hat Enterprise Linux 7 | firefox-0:52.2.0-1.el7_3 | Fixed | RHSA-2017:1440 |
| Red Hat Enterprise Linux 7 | thunderbird-0:52.2.0-1.el7_3 | Fixed | RHSA-2017:1561 |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
AV:N/AC:L/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.00% (0.02002) | 80.02th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.02% (0.02019) | 78.33th | v5 (v2026.06.15) |
| Mar 17, 2025 | 1.24% (0.01245) | 77.92th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.31% (0.00310) | 70.87th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.31% (0.00306) | 68.98th | v3 (v2023.03.01) |
| Nov 2, 2023 | 0.31% (0.00306) | 66.50th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.27% (0.00266) | 63.44th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.25% (0.00252) | 61.23th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.54% (0.01537) | 51.33th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.48% (0.02476) | 54.92th | v5 (v2026.06.15) |
| Apr 14, 2021 | 2.48% (0.02476) | 0.00th | v1 |
References (16)
- http://www.securityfocus.com/bid/99057 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1038689 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts x_refsource_MISCThird Party Advisory
- https://access.redhat.com/errata/RHSA-2017:1440 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/errata/RHSA-2017:1561 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2017-7764 Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1364283 x_refsource_CONFIRMExploitIssue TrackingVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1461262 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2017-7764
- https://www.cve.org/CVERecord?id=CVE-2017-7764
- https://www.debian.org/security/2017/dsa-3881 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.debian.org/security/2017/dsa-3918 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.mozilla.org/en-US/security/advisories/mfsa2017-16/#CVE-2017-7764
- https://www.mozilla.org/security/advisories/mfsa2017-15/ x_refsource_CONFIRMVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-16/ x_refsource_CONFIRMVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-17/ x_refsource_CONFIRMVendor Advisory
Change history (0)
No recorded changes yet.