Title

Firefox must not recommend extensions as the user is using the browser. (Cat II impact)

Discussion

The Recommended Extensions program recommends extensions to users as they surf the web. The user must not be encouraged to install extensions from the websites they visit. Allowed extensions are to be centrally managed.

Check Content

Type "about:policies" in the browser address bar. If "UserMessaging" is not displayed under Policy Name or the Policy Value is not "ExtensionRecommendations" with a value of "false", this is a finding.

Fix Text

Windows group policy: 1. Open the group policy editor tool with "gpedit.msc". 2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Mozilla\Firefox\User Messaging Policy Name: Extension Recommendations Policy State: Disabled macOS "plist" file: Add the following: <key>UserMessaging</key> <dict> <key>ExtensionRecommendations</key> <false/> </dict> Linux "policies.json" file: Add the following in the policies section: "UserMessaging": { "ExtensionRecommendations": false }

Additional Identifiers

Rule ID: SV-251572r879587_rule

Vulnerability ID: V-251572

Group Title: SRG-APP-000141

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.