Firefox must not recommend extensions as the user is using the browser.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-251572 | FFOX-00-000028 | SV-251572r960963_rule | CCI-000381 | medium |
| Description | ||||
| 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. | ||||
| STIG | Date | |||
| Mozilla Firefox Security Technical Implementation Guide | 2025-02-11 | |||
Details
Check Text (C-251572r960963_chk)
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 (F-54961r807187_fix)
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
}