Firefox must be configured to not automatically update installed add-ons and plugins.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-251549 | FFOX-00-000005 | SV-251549r960963_rule | CCI-000381 | medium |
| Description | ||||
| 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. | ||||
| STIG | Date | |||
| Mozilla Firefox Security Technical Implementation Guide | 2025-02-11 | |||
Details
Check Text (C-251549r960963_chk)
Type "about:policies" in the browser window.
If "ExtensionUpdate" is not displayed under Policy Name or the Policy Value is not "false", this is a finding.
Fix Text (F-54938r807118_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\Extensions
Policy Name: Extension Update
Policy State: Disabled
macOS "plist" file:
Add the following:
<key>ExtensionUpdate</key>
<false/>
Linux "policies.json" file:
Add the following in the policies section:
"ExtensionUpdate": false