Title

The macOS system must be configured to disable Bonjour multicast advertising. (Cat II impact)

Discussion

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 can provide 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.

Check Content

Verify the macOS system is configured to disable Bonjour multicast advertising with the following command: /usr/sbin/system_profiler SPConfigurationProfileDataType | /usr/bin/grep "NoMulticastAdvertisements" NoMulticastAdverstisements = 1; If there is no result, or if "NoMulticastAdvertisements" is not set to "1", this is a finding.

Fix Text

Configure the macOS system to disable Bonjour multicast advertising by installing the "Custom Policy" configuration profile.

Additional Identifiers

Rule ID: SV-257188r905197_rule

Vulnerability ID: V-257188

Group Title: SRG-OS-000095-GPOS-00049

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.