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Vulnerability details: VCID-sy78-y9qc-3ug1
Vulnerability ID VCID-sy78-y9qc-3ug1
Aliases CVE-2017-7764
Summary 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."
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-20 Improper Input Validation
System Score Found at
cvssv3 5.3 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2017-7764.json
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
epss 0.01202 https://api.first.org/data/v1/epss?cve=CVE-2017-7764
cvssv2 4 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3 4.2 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 5.0 https://nvd.nist.gov/vuln/detail/CVE-2017-7764
cvssv3 5.3 https://nvd.nist.gov/vuln/detail/CVE-2017-7764
archlinux Critical https://security.archlinux.org/AVG-302
archlinux Critical https://security.archlinux.org/AVG-303
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2017-15
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2017-16
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2017-17
Reference id Reference type URL
https://access.redhat.com/errata/RHSA-2017:1440
https://access.redhat.com/errata/RHSA-2017:1561
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2017-7764.json
https://api.first.org/data/v1/epss?cve=CVE-2017-7764
https://bugzilla.mozilla.org/show_bug.cgi?id=1364283
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5470
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5472
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7749
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7750
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7751
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7752
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7754
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7756
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7757
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7758
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7764
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7771
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7772
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7773
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7774
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7776
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7777
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7778
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://www.debian.org/security/2017/dsa-3881
https://www.debian.org/security/2017/dsa-3918
https://www.mozilla.org/security/advisories/mfsa2017-15/
https://www.mozilla.org/security/advisories/mfsa2017-16/
https://www.mozilla.org/security/advisories/mfsa2017-17/
http://www.securityfocus.com/bid/99057
http://www.securitytracker.com/id/1038689
http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts
1461262 https://bugzilla.redhat.com/show_bug.cgi?id=1461262
ASA-201706-19 https://security.archlinux.org/ASA-201706-19
ASA-201706-20 https://security.archlinux.org/ASA-201706-20
AVG-302 https://security.archlinux.org/AVG-302
AVG-303 https://security.archlinux.org/AVG-303
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
CVE-2017-7764 https://nvd.nist.gov/vuln/detail/CVE-2017-7764
mfsa2017-15 https://www.mozilla.org/en-US/security/advisories/mfsa2017-15
mfsa2017-16 https://www.mozilla.org/en-US/security/advisories/mfsa2017-16
mfsa2017-17 https://www.mozilla.org/en-US/security/advisories/mfsa2017-17
USN-3315-1 https://usn.ubuntu.com/3315-1/
USN-3321-1 https://usn.ubuntu.com/3321-1/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2017-7764.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:H/Au:N/C:P/I:N/A:P Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2017-7764
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2017-7764
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.78078
EPSS Score 0.01202
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:19.543755+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2017/mfsa2017-17.yml 37.0.0