Mozilla Firefox Security Technical Implementation Guide

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

The Telemetry feature provides this capability by sending performance and usage info to Mozilla. As you use Firefox, Telemetry measures and collects non-personal information, such as performance, hardware, usage and customizations. It then sends this information to Mozilla on a daily basis and we use it to improve Firefox.

The Telemetry feature provides this capability by sending performance and usage info to Mozilla. As you use Firefox, Telemetry measures and collects non-personal information, such as performance, hardware, usage and customizations. It then sends this information to Mozilla on a daily basis and we use it to improve Firefox.

The Content Blocking/Tracking Protection feature stops Firefox from loading content from malicious sites. The content might be a script or an image, for example. If a site is on one of the tracker lists you set Firefox to use, then the fingerprinting script (or other tracking script/image) will not be loaded from that site. Fingerprinting scripts collect information about your browser and device configuration, such as your operating system, screen resolution, and other settings. By compiling these pieces of data, fingerprinters create a unique profile of you that can be used to track you around the Web.

The Content Blocking/Tracking Protection feature stops Firefox from loading content from malicious sites. The content might be a script or an image, for example. If a site is on one of the tracker lists you set Firefox to use, then the fingerprinting script (or other tracking script/image) will not be loaded from that site. Cryptomining scripts use your computer’s central processing unit (CPU) to invisibly mine cryptocurrency.

Tracking generally refers to content, cookies, or scripts that can collect your browsing data across multiple sites.

The Recommended Extensions program will make it easier for users to discover extensions that have been reviewed for security, functionality, and user experience.

A weak cipher is defined as an encryption/decryption algorithm that uses a key of insufficient length. Using an insufficient length for a key in an encryption/decryption algorithm opens up the possibility (or probability) that the encryption scheme could be broken.