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

An XCCDF Rule

Description

<VulnDiscussion>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.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>

ID: SV-251554r879587_rule
Severity: Medium
References: CCI-000381
Updated: about 1 year ago

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 - Manual Procedure