Firefox must be configured to not automatically update installed add-ons and plugins.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-251549 | SRG-APP-000141 | FFOX-00-000005 | SV-251549r960963_rule | 2026-05-08 | 6 |
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.
ℹ️ Check
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
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