Firefox extension recommendations must be disabled.

The Recommended Extensions program makes it easier for users to discover extensions that have been reviewed for security, functionality, and user experience. Allowed extensions are to be centrally managed.

Type "about:policies" in the browser address bar.

If "Preferences" is not displayed under Policy Name and the Policy Value does not include "extensions.htmlaboutaddons.recommendations.enabled" with a value of "false" and status of "locked", this is a finding.

Windows group policy: 1. Open the group policy editor tool with "gpedit.msc". 2. Navigate to Policy Path: Computer Configuration\Administrative Templates\Mozilla\Firefox\ Policy Name: Preferences Policy State: Enabled Policy Value: { "extensions.htmlaboutaddons.recommendations.enabled": { "Value": false, "Status": "locked" } }

macOS "plist" file: Add the following: <key>Preferences</key> <dict> <key>extensions.htmlaboutaddons.recommendations.enabled</key> <dict> <key>Value</key> <false/> <key>Status</key> <string>locked</string> </dict> </dict>

Linux "policies.json" file: Add the following in the policies section: "Preferences": { "extensions.htmlaboutaddons.recommendations.enabled": { "Value": false, "Status": "locked" },