Firefox accounts must be disabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-251578	SRG-APP-000141	FFOX-00-000034	SV-251578r960963_rule	2025-02-11	6

Description
Disable Firefox Accounts integration (Sync). It is detrimental for applications to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Applications are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include but are not limited to advertising software or browser plug-ins that are not related to requirements or provide a wide array of functionality not required for every mission but that cannot be disabled.

Description

Disable Firefox Accounts integration (Sync). It is detrimental for applications to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Applications are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include but are not limited to advertising software or browser plug-ins that are not related to requirements or provide a wide array of functionality not required for every mission but that cannot be disabled.

ℹ️ Check
Type "about:policies" in the browser address bar. If "DisableFirefoxAccounts" is not displayed under Policy Name or the Policy Value is not "true", 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\ Policy Name: Disable Firefox Accounts Policy State: Enabled macOS "plist" file: <key>DisableFirefoxAccounts</key> <true/> Linux "policies.json" file: Add the following in the policies section: "DisableFirefoxAccounts": true