What’s Vulnerable › Vulnerabilities

CVE-2017-7763

• Severity: medium (CVSS 5.3 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-20

Description

Default fonts on OS X display some Tibetan characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

Affected products

• Debian Linux: 8.0, 9.0
• Mozilla Firefox: before 52.2.0; before 54.0 — fixed in 52.2.0, 54.0
• Mozilla Thunderbird: before 52.2.0 — fixed in 52.2.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 52.2.0, 54.0; Mozilla Thunderbird 52.2.0. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/99057
• http://www.securitytracker.com/id/1038689
• https://bugzilla.mozilla.org/show_bug.cgi?id=1360309
• 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
• https://bugzilla.mozilla.org/show_bug.cgi?id=1360309
• https://www.mozilla.org/security/advisories/mfsa2017-15/
• https://www.mozilla.org/security/advisories/mfsa2017-16/
• https://www.mozilla.org/security/advisories/mfsa2017-17/

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