Rapid7

vulnerability

Red Hat: CVE-2021-43538: Missing fullscreen and pointer lock notification when requesting both (Multiple Advisories)

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
Dec 8, 2021
Added
Dec 9, 2021
Modified
Mar 27, 2026

Description

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

Solutions

redhat-upgrade-firefoxredhat-upgrade-firefox-debuginforedhat-upgrade-firefox-debugsourceredhat-upgrade-thunderbirdredhat-upgrade-thunderbird-debuginforedhat-upgrade-thunderbird-debugsource

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.