Firefox is configured to allow JavaScript to disable or replace context menus.

From Mozilla Firefox Security Technical Implementation Guide

Part of DTBF183 - JavaScript Context Menus

SV-16928r2_rule Firefox is configured to allow JavaScript to disable or replace context menus.

Vulnerability discussion

A context menu (also known as a pop-up menu) is often used in a graphical user interface (GUI) and appears upon user interaction (e.g., a right mouse click). A context menu offers a limited set of choices that are available in the current state, or context, of the operating system or application. A website may execute JavaScript that can make changes to these context menus. This can help disguise an attack. Set this preference to "false" so that webpages will not be able to affect the context menu event.

Check content

Type "about:config" in the address bar of the browser. Verify that the preferences "dom.event.contextmenu.enabled" is set and locked to "false". Criteria: If the parameter is set incorrectly, then this is a finding. If the setting is not locked, this is a finding.

Fix text

Ensure the preferences "dom.event.contextmenu.enabled" is set and locked to "false".

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.