Software Engineering Institute

Certain Mozilla web browser status elements, such as the address bar, status bar, and navigation controls, can be disabled remotely by web sites using JavaScript. Consequently, attackers can design malicious web sites that disable these native elements and, using XUL, recreate pages that look like native Mozilla dialogs and windows. (XUL is Mozilla's XML-based user interface. It allows for the development of cross-platform applications.)

An attacker could convince a user that they were viewing a native Mozilla dialog, when in fact they are visiting a page created by the attacker. The attacker could use additional social engineering techniques to trick the victim into disclosing sensitive information such as credit card numbers, account numbers, and passwords. The attacker could also spoof pop-up windows that do not display the address bar.

Disable the ability to hide status items

By performing the following steps, it is possible to prevent JavaScript from disabling status elements. This will make XUL-created pages appear distinct from native Mozilla dialogs.

1. Enter "about:config" in Mozilla's address bar. This will display Mozilla's configuration values.
2. Set the following values to true:

dom.disable_window_open_feature.titlebar
dom.disable_window_open_feature.close
dom.disable_window_open_feature.toolbar
dom.disable_window_open_feature.location
dom.disable_window_open_feature.directories
dom.disable_window_open_feature.personalbar
dom.disable_window_open_feature.menubar
dom.disable_window_open_feature.scrollbars
dom.disable_window_open_feature.resizable
dom.disable_window_open_feature.minimizable
dom.disable_window_open_feature.status