The macOS system must be configured to disable Bonjour multicast advertising.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-81605	AOSX-13-000545	SV-96319r1_rule		Medium

Description
To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems 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. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. Bonjour multicast advertising must be disabled on the system.

Description

To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems 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. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. Bonjour multicast advertising must be disabled on the system.

STIG	Date
Apple OS X 10.13 Security Technical Implementation Guide	2020-05-29

Details

Check Text ( C-81381r1_chk )
To check if Bonjour multicast advertising has been disabled, run the following command: /usr/bin/sudo /usr/bin/defaults read /Library/Preferences/com.apple.mDNSResponder \| /usr/bin/grep NoMulticastAdvertisements If an error is returned, nothing is returned, or "NoMulticastAdvertisements" is not set to "1", this is a finding.

Fix Text (F-88453r1_fix)
To configure Bonjour to disable multicast advertising, run the following command: /usr/bin/sudo /usr/bin/defaults write /Library/Preferences/com.apple.mDNSResponder.plist NoMulticastAdvertisements -bool true The system will need to be restarted for the update to take effect.