STIGUI
V-251555CAT II — Medium severitySV-251555r1067556_rule

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

Rule version FFOX-00-000011 · STIG v6 · 2026-08-19

Discussion

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.

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" } }

Identifiers

Group ID
V-251555
Group title
SRG-APP-000141
Rule ID
SV-251555r1067556_rule
Check ID
C-54990r1067555_chk
Fix ID
F-54944r807136_fix