Firefox must be configured to prevent JavaScript from raising or lowering windows.

JavaScript can raise and lower browser windows to cause improper input. Configure the browser setting to prevent scripts on visited websites from raising and lowering browser windows.

Type "about:policies" in the browser address bar. If "Preferences" is not displayed under Policy Name or the Policy Value does not include "dom.disable_window_flip" with a value of "true" and status of "locked", this is a finding.

Windows group policy: 1. Open the group policy editor tool with "gpedit.msc". 2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Mozilla\Firefox\ Policy Name: Preferences Policy State: Enabled Policy Value: { "dom.disable_window_flip": { "Value": true, "Status": "locked" } } macOS "plist" file: Add the following: <key>Preferences</key> <dict> <key>dom.disable_window_flip</key> <dict> <key>Value</key> <true/> <key>Status</key> <string>locked</string> </dict> </dict> Linux "policies.json" file: Add the following in the policies section: "Preferences": { "dom.disable_window_flip": { "Value": true, "Status": "locked" } }