Firefox must be configured to prevent JavaScript from moving or resizing windows.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-251554 | FFOX-00-000010 | SV-251554r879587_rule | Medium |
| Description |
| JavaScript can make changes to the browser's appearance. This activity can help disguise an attack taking place in a minimized background window. Configure the browser setting to prevent scripts on visited websites from moving and resizing browser windows. |
| STIG | Date |
| Mozilla Firefox Security Technical Implementation Guide | 2023-06-05 |
Details
| Check Text (C-54989r807132_chk) |
| Type "about:policies" in the browser address bar. If "dom.disable_window_move_resize" is not displayed with a value of "true", this is a finding. |
| Fix Text (F-54943r807133_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_move_resize": { "Value": true, "Status": "locked" } } macOS "plist" file: Add the following: <key>Preferences</key> <dict> <key>dom.disable_window_move_resize</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_move_resize": { "Value": true, "Status": "locked" } } |