Mozilla · Firefox · CVE-2020-6810
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 74
**Description**
A issue exists where a website in fullscreen mode can use a previously opened popup to obscure the notification indicating the browser is in fullscreen mode. When combined with spoofing the browser chrome, this can confuse the user about the current origin of the page, potentially leading to credential theft or other attacks.
**Recommendations**
For Firefox versions prior to 74, update to version 74 or later to resolve the issue.