2.4.12 Ensure Media Sharing Is Disabled

Information

Starting with macOS 10.15, Apple has provided a control which permits a user to share Apple downloaded content on all Apple devices that are signed in with the same Apple ID. This allows users to share downloaded Movies, Music, or TV shows with other controlled macOS, iOS and iPadOS devices, as well as photos with Apple TVs.

With this capability, guest users can also use media downloaded on the computer.

The recommended best practice is not to use the computer as a server, but to utilize Apple's cloud storage in order to download and use content stored there if content stored with Apple is used on multiple devices. https://support.apple.com/guide/mac-help/set-up-media-sharing-on-mac-mchlp13371337/mac

Rationale:

Disabling Media Sharing reduces the remote attack surface of the system.

Impact:

Media Sharing allows for pre-downloaded content on a Mac to be available to other Apple devices on the same network. Leaving this disabled forces device users to stream or download content from each Apple authorized device. This sharing could even allow unauthorized devices on the same network media access.

Solution

Perform the following to disable Media Sharing:
Graphical Method:

Open System Preferences

Select Sharing

Uncheck Media Sharing

Terminal Method:
Run the following command to disable Media Sharing:

$ sudo -u <username> defaults write com.apple.amp.mediasharingd home-sharing-enabled -int 0

example:

$ sudo -u test2 defaults write com.apple.amp.mediasharingd home-sharing-enabled -int 0

Profile Method:

Create or edit a configuration profile with the PayLoadType of com.apple.preferences.sharing.SharingPrefsExtension

Add the key homeSharingUIStatus

Set the key to <integer>0</integer>

Add the key legacySharingUIStatus

Set the key to <integer>0</integer>

Add the key mediaSharingUIStatus

Set the key to <integer>0</integer>

See Also

https://workbench.cisecurity.org/files/4000

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION

References: 800-53|CM-1, 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|CM-7(1), 800-53|CM-9, 800-53|SA-3, 800-53|SA-8, 800-53|SA-10, CSCv7|5.1, CSCv7|9.2

Plugin: Unix

Control ID: 004099144c4e80cfc24f675f6e2468cc7cafc25fb433ffa5fafd8e4cd2308e2c