Information
This setting disables the ability to view HTTP content such as JavaScript, CSS, objects, and xhr requests.
Rationale:
Blocking active mixed content minimizes the risk of man-in-the-middle attacks.
Impact:
None - This is the default behavior.
Solution
To establish the recommended configuration, set security.mixed_content.block_active_content to true:
Type about:config in the address bar
Type security.mixed_content.block_active_content in the filter
Ensure the setting is set as prescribed.
OR
Open the mozilla.cfg file in the installation directory with a text editor
Add the following lines to mozilla.cfg:
lockPref('security.mixed_content.block_active_content', true);
Default Value:
True