Firefox must be configured to prevent JavaScript from moving or resizing windows.

An XCCDF Rule

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.

ID: SV-251554r879587_rule
Version: FFOX-00-000010
Severity: Medium
References: CCI-000381
Updated: 15 days ago

Remediation Templates

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"
  }
}

Firefox must be configured to prevent JavaScript from moving or resizing windows.

Description

Remediation Templates

A Manual Procedure