Mozilla Firefox Security Technical Implementation Guide

When a web site asks for a certificate for user authentication, Firefox must be configured to have the user choose which certificate to present. Websites within DOD require user authentication for access which increases security for DoD information. Access will be denied to the user if certificate management is not configured.System Administrator

Although current versions of Firefox have this set to disabled by default, use of this option can be harmful. This would allow the browser to access the Windows shell. This could allow access to the underlying system. This check verifies that the default setting has not been changed. System Administrator

New file types cannot be added directly to the helper applications or plugins listing. Files with these extensions will not be allowed to use Firefox publicly available plugins and extensions to open. The application will be configured to open these files using external applications only. After a helper application or save to disk download action has been set, that action will be taken automatically for those types of files. When the user receives a dialog box asking if you want to save the file or open it with a specified application, this indicates that a plugin does not exist. The user has not previously selected a download action or helper application to automatically use for that type of file. When prompted, if the user checks the option to Do this automatically for files like this from now on, then an entry will appear for that type of file in the plugins listing and this file type is automatically opened in the future. This can be a security issue. New file types cannot be added directly to the Application plugin listing. System Administrator

In order to protect privacy and sensitive data, Firefox provides the ability to configure Firefox such that data entered into forms is not saved. This mitigates the risk of a website gleaning private information from prefilled information.System Administrator

While on the internet, it may be possible for an attacker to view the saved password files and gain access to the user's accounts on various hosts. System Administrator

Firefox can be set to store passwords for sites visited by the user. These individual passwords are stored in a file and can be protected by a master password. Autofill of the password can then be enabled when the site is visited. This feature could also be used to autofill the certificate pin which could lead to compromise of DoD information.System Administrator

Popup windows may be used to launch an attack within a new browser window with altered settings. This setting blocks popup windows created while the page is loading.System Administrator

JavaScript can make changes to the browser’s appearance. This activity can help disguise an attack taking place in a minimized background window. Set browser setting to prevent scripts on visited websites from moving and resizing browser windows. System Administrator

Use of versions prior to TLS 1.1 are not permitted. SSL 2.0 and SSL 3.0 contain a number of security flaws. These versions must be disabled in compliance with the Network Infrastructure and Secure Remote Computing STIGs.System Administrator

JavaScript can make changes to the browser’s appearance. Allowing a website to use JavaScript to raise and lower browser windows may disguise an attack. Browser windows may not be set as active via JavaScript. System Administrator

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.System Administrator

Set this to false to disable checking for updated versions of the Extensions/Themes. Automatic updates from untrusted sites puts the enclave at risk of attack and may override security settings.System Administrator

Locked settings prevent users from accessing about:config and changing the security settings set by the system administrator. Locked settings should be placed in the mozilla.cfg file. The mozilla.cfg file is an encoded file of JavaScript commands. The encoding is a simple "byte-shifting" with an offset of 13 (Netscape 4 used a similar encoding, but with a 7 instead). This file also needs to be "called" from the configuration file local-settings.jsSystem Administrator

Updates need to be controlled and installed from authorized and trusted servers. This setting overrides a number of other settings which may direct the application to access external URLs.System AdministratorECSC-1

A browser extension is a program that has been installed into the browser which adds functionality to it. Where a plug-in interacts only with a web page and usually a third party external application (Flash, Adobe Reader) an extension interacts with the browser program itself. Extensions are not embedded in web pages and must be downloaded and installed in order to work. Extensions allow browsers to avoid restrictions which apply to web pages. For example, an extension can be written to combine data from multiple domains and present it when a certain page is accessed which can be considered Cross Site Scripting. If a browser is configured to allow unrestricted use of extension then plug-ins can be loaded and installed from malicious sources and used on the browser.System Administrator

There should be no background submission of technical and other information from DoD computers to Mozilla with portions posted publically.