What’s Vulnerable › Vulnerabilities

CVE-2017-5383

• Severity: medium (CVSS 5.3 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% 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

URLs containing certain unicode glyphs for alternative hyphens and quotes do not properly trigger punycode display, allowing for domain name spoofing attacks in the location bar. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Affected products

• Debian Linux: 8.0
• Mozilla Firefox: before 51.0; before 45.7.0 — fixed in 45.7.0, 51.0
• Mozilla Thunderbird: before 45.7.0 — fixed in 45.7.0
• Red Hat Enterprise Linux: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Desktop: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Server: 5.0, 6.0, 7.0
• RedHat Enterprise Linux Server Aus: 7.3, 7.4
• RedHat Enterprise Linux Server Eus: 7.3, 7.4, 7.5
• RedHat Enterprise Linux Workstation: 5.0, 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 45.7.0, 51.0; Mozilla Thunderbird 45.7.0. Check the vendor advisory for mitigations.

References

• http://rhn.redhat.com/errata/RHSA-2017-0190.html
• http://rhn.redhat.com/errata/RHSA-2017-0238.html
• http://www.securityfocus.com/bid/95769
• http://www.securitytracker.com/id/1037693
• https://bugzilla.mozilla.org/show_bug.cgi?id=1323338
• https://bugzilla.mozilla.org/show_bug.cgi?id=1324716
• https://security.gentoo.org/glsa/201702-13
• https://security.gentoo.org/glsa/201702-22
• https://www.debian.org/security/2017/dsa-3771
• https://www.debian.org/security/2017/dsa-3832
• https://www.mozilla.org/security/advisories/mfsa2017-01/
• https://www.mozilla.org/security/advisories/mfsa2017-02/

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