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

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-251555	SRG-APP-000141	FFOX-00-000011	SV-251555r1067556_rule	2025-02-11	6

Description
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.

ℹ️ Check
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.

✔️ Fix
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" } }

✔️ Fix

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" } }