What’s Vulnerable › Vulnerabilities

CVE-2017-5451

• Severity: medium (CVSS 4.3 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-06-11 · updated 2026-06-17
• Weakness: CWE-20

Description

A mechanism to spoof the addressbar through the user interaction on the addressbar and the "onblur" event. The event could be used by script to affect text display to make the loaded site appear to be different from the one actually loaded within the addressbar. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

Affected products

• Mozilla Firefox: before 53.0; before 52.1.0 — fixed in 52.1.0, 53.0
• Mozilla Thunderbird: before 52.1.0 — fixed in 52.1.0
• Red Hat Enterprise Linux: 6.0, 7.0
• RedHat Enterprise Linux Desktop: 6.0, 7.0
• RedHat Enterprise Linux Server: 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: 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 52.1.0, 53.0; Mozilla Thunderbird 52.1.0. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/97940
• http://www.securitytracker.com/id/1038320
• https://access.redhat.com/errata/RHSA-2017:1106
• https://access.redhat.com/errata/RHSA-2017:1201
• https://bugzilla.mozilla.org/show_bug.cgi?id=1273537
• https://www.mozilla.org/security/advisories/mfsa2017-10/
• https://www.mozilla.org/security/advisories/mfsa2017-12/
• https://www.mozilla.org/security/advisories/mfsa2017-13/
• http://www.securityfocus.com/bid/97940
• http://www.securitytracker.com/id/1038320
• https://access.redhat.com/errata/RHSA-2017:1106
• https://access.redhat.com/errata/RHSA-2017:1201

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