ExtensionSettings

Manage all aspects of extensions. This policy is based heavily on the Chrome policy of the same name.

This policy maps an extension ID to its configuration. With an extension ID, the configuration will be applied to the specified extension only. A default configuration can be set for the special ID *, which will apply to all extensions that don't have a custom configuration set in this policy.

To obtain an extension ID, install the extension and go to about:support. You will see the ID in the Extensions section. You can download am extension on AMO that makes it easy to find the ID of extensions. Alternatively, the Mozilla Addons API returns the ID as guid: https://addons.mozilla.org/api/v5/addons/addon/ublock-origin/

Compatibility: Firefox 69, Firefox ESR 68.1 (As of Firefox 85, Firefox ESR 78.7, installing a theme makes it the default.)
CCK2 Equivalent: N/A
Preferences Affected: N/A

Values

The configuration for each extension is a dictionary that can contain the fields documented below.

Name	Description
`installation_mode`	Maps to a string indicating the installation mode for the extension. The valid strings are `allowed`,`blocked`,`force_installed`, and `normal_installed`.
`allowed`	Allows the extension to be installed by the user. This is the default behavior. There is no need for an install_url; it will automatically be allowed based on the ID.
`blocked`	Blocks installation of the extension and removes it from the device if already installed.
`force_installed`	The extension is automatically installed and can't be removed by the user. This option is not valid for the default configuration and requires an install_url.
`normal_installed`	The extension is automatically installed but can be disabled by the user. This option is not valid for the default configuration and requires an install_url.
`install_url`	Maps to a URL indicating where Firefox can download a force_installed or normal_installed extension. If installing from the local file system, use a `file:///` URL. If installing from the addons.mozilla.org, use the following URL (substituting ID with the extension ID or with the short name from the URL on AMO), https://addons.mozilla.org/firefox/downloads/latest/ID/latest.xpi. Languages packs are available from https://releases.mozilla.org/pub/firefox/releases/VERSION/PLATFORM/xpi/LANGUAGE.xpi. If you need to update the extension, you can change the name of the extension and it will be automatically updated. Extensions installed from file URLs will additional be updated when their internal version changes.
`install_sources`	A list of sources from which installing extensions is allowed using URL match patterns. This is unnecessary if you are only allowing the installation of certain extensions by ID. Each item in this list is an extension-style match pattern. Users will be able to easily install items from any URL that matches an item in this list. Both the location of the *.xpi file and the page where the download is started from (i.e. the referrer) must be allowed by these patterns. This setting can be used only for the default configuration.
`allowed_types`	This setting whitelists the allowed types of extension/apps that can be installed in Firefox. The value is a list of strings, each of which should be one of the following: "extension", "theme", "dictionary", "locale" This setting can be used only for the default configuration.
`blocked_install_message`	This maps to a string specifying the error message to display to users if they're blocked from installing an extension. This setting allows you to append text to the generic error message displayed when the extension is blocked. This could be be used to direct users to your help desk, explain why a particular extension is blocked, or something else. This setting can be used only for the default configuration.
`restricted_domains`	An array of domains on which content scripts can't be run. This setting can be used only for the default configuration.
`updates_disabled`	(Firefox 89, Firefox ESR 78.11) Boolean that indicates whether or not to disable automatic updates for an individual extension.
`default_area`	(Firefox 113) String that indicates where to place the extension icon by default. Possible values are `navbar` and `menupanel`.
`temporarily_allow_weak_signatures`	(Firefox 127) A boolean that indicates whether to allow installing extensions signed using deprecated signature algorithms.
`private_browsing`	(Firefox 136, Firefox ESR 128.8) A boolean that indicates whether or not this extension should be enabled in private browsing.

Windows (GPO)

Software\Policies\Mozilla\Firefox\ExtensionSettings (REG_MULTI_SZ) =

{
  "*": {
    "blocked_install_message": "Custom error message.",
    "install_sources": ["https://yourwebsite.com/*"],
    "installation_mode": "blocked",
    "allowed_types": ["extension"]
  },
  "uBlock0@raymondhill.net": {
    "installation_mode": "force_installed",
    "install_url": "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi"  # using slug / short name
  },
  "adguardadblocker@adguard.com": {
    "installation_mode": "force_installed",
    "install_url": "https://addons.mozilla.org/firefox/downloads/latest/adguardadblocker@adguard.com/latest.xpi"  # using extension ID
  },
  "https-everywhere@eff.org": {
    "installation_mode": "allowed",
    "updates_disabled": false
  }
}

Windows (Intune)

OMA-URI:

./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Extensions/ExtensionSettings

Value (string):

<enabled/>
<data id="ExtensionSettings" value='
{
  "*": {
    "blocked_install_message": "Custom error message.",
    "install_sources": ["https://yourwebsite.com/*"],
    "installation_mode": "blocked",
    "allowed_types": ["extension"]
  },
  "uBlock0@raymondhill.net": {
    "installation_mode": "force_installed",
    "install_url": "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi"
  },
  "adguardadblocker@adguard.com": {
    "installation_mode": "force_installed",
    "install_url": "https://addons.mozilla.org/firefox/downloads/latest/adguardadblocker@adguard.com/latest.xpi"
  },
  "https-everywhere@eff.org": {
    "installation_mode": "allowed",
    "updates_disabled": false
  }
}'/>

If you are using custom ADMX and ADML administrative templates in Intune, you can use this OMA-URI instead to workaround the limit on the length of strings. Put all of your JSON on one line.

OMA-URI:

./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Extensions/ExtensionSettingsOneLine

Value (string):

<enabled/>
<data id="JSONOneLine" value='{}'/>

macOS

<dict>
  <key>ExtensionSettings</key>
  <dict>
    <key>*</key>
    <dict>
      <key>blocked_install_message</key>
      <string>Custom error message.</string>
      <key>install_sources</key>
      <array>
        <string>"https://yourwebsite.com/*"</string>
      </array>
      <key>installation_mode</key>
      <string>blocked</string>
      <key>allowed_types</key>
      <array>
        <string>extension</string>
      </array>
    </dict>
    <key>uBlock0@raymondhill.net</key>
    <dict>
      <key>installation_mode</key>
      <string>force_installed</string>
      <key>install_url</key>
      <string>https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi</string>
    </dict>
    <key>adguardadblocker@adguard.com</key>
    <dict>
      <key>installation_mode</key>
      <string>force_installed</string>
      <key>install_url</key>
      <string>https://addons.mozilla.org/firefox/downloads/latest/adguardadblocker@adguard.com/latest.xpi</string>
    </dict>
    <key>https-everywhere@eff.org</key>
    <dict>
      <key>installation_mode</key>
      <string>allowed</string>
      <key>updates_disabled</key>
      <true/> | <false/>
    </dict>
  </dict>
</dict>

policies.json

{
  "policies": {
    "ExtensionSettings": {
      "*": {
        "blocked_install_message": "Custom error message.",
        "install_sources": ["https://yourwebsite.com/*"],
        "installation_mode": "blocked",
        "allowed_types": ["extension"]
      },
      "uBlock0@raymondhill.net": {
        "installation_mode": "force_installed",
        "install_url": "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi"
      },
      "adguardadblocker@adguard.com": {
        "installation_mode": "force_installed",
        "install_url": "https://addons.mozilla.org/firefox/downloads/latest/adguardadblocker@adguard.com/latest.xpi"
      },
      "https-everywhere@eff.org": {
        "installation_mode": "allowed",
        "updates_disabled": false
      }
    }
  }
}