CVE-2017-7770

Severity: medium (CVSS 5.9 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

A mechanism where when a new tab is loaded through JavaScript events, if fullscreen mode is then entered, the addressbar will not be rendered. This would allow a malicious site to displayed a spoofed addressbar, showing the location of an arbitrary website instead of the one loaded. Note: this issue only affects Firefox for Android. Desktop Firefox is unaffected. This vulnerability affects Firefox < 54.

Affected products

Mozilla Firefox: before 54.0 — fixed in 54.0

How to fix

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

References

http://www.securityfocus.com/bid/99049
http://www.securitytracker.com/id/1038689
https://bugzilla.mozilla.org/show_bug.cgi?id=1317242
https://www.mozilla.org/security/advisories/mfsa2017-15/
http://www.securityfocus.com/bid/99049
http://www.securitytracker.com/id/1038689
https://bugzilla.mozilla.org/show_bug.cgi?id=1317242
https://www.mozilla.org/security/advisories/mfsa2017-15/

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