Firefox autoplay must be disabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
low	V-251565	SRG-APP-000141	FFOX-00-000021	SV-251565r960963_rule	2025-02-11	6

Description
Autoplay allows the user to control whether videos can play automatically (without user consent) with audio content. The user must be able to select content that is run within the browser window.

ℹ️ Check
Type "about:policies" in the browser address bar. If "Permissions" is not displayed under Policy Name or the Policy Value is not "Autoplay" with a value of "Default" and "Block-audio-video", 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\Permissions\Autoplay Policy Name: Default autoplay level Policy State: Enabled Policy Value: Block Audio and Video macOS "plist" file: Add the following: <key>Permissions</key> <dict> <key>Autoplay</key> <dict> <string>block-audio-video</string> </dict> </dict> Linux "policies.json" file: Add the following in the policies section: "Permissions": { "Autoplay": { "Default": "block-audio-video" } }

✔️ 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\Permissions\Autoplay Policy Name: Default autoplay level Policy State: Enabled Policy Value: Block Audio and Video macOS "plist" file: Add the following: <key>Permissions</key> <dict> <key>Autoplay</key> <dict> <string>block-audio-video</string> </dict> </dict> Linux "policies.json" file: Add the following in the policies section: "Permissions": { "Autoplay": { "Default": "block-audio-video" } }