The macOS system must restrict the ability to utilize external writeable media devices.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-250320	APPL-11-005051	SV-250320r818791_rule		Medium

Description
External writeable media devices must be disabled for users. External USB devices are a potential vector for malware and can be used to exfiltrate sensitive data.

STIG	Date
Apple macOS 11 (Big Sur) Security Technical Implementation Guide	2022-11-18

Details

Check Text ( C-53755r818790_chk )
Verify the system is configured to disable external writeable media devices: $ /usr/sbin/system_profiler SPConfigurationProfileDataType \| /usr/bin/egrep -A 3 'blankbd\|blankcd\|blankdvd\|dvdram\|harddisk-external' “blankbd" = ( deny, eject ); “blankcd" = ( deny, eject ); “blankdvd" = ( deny, eject ); “dvdram" = ( deny, eject ); “harddisk-external" = ( deny, eject ); If the result does not match the output above and the external writeable media devices have not been approved by the Authorizing Official, this is a finding.

Check Text ( C-53755r818790_chk )

Verify the system is configured to disable external writeable media devices:
$ /usr/sbin/system_profiler SPConfigurationProfileDataType | /usr/bin/egrep -A 3 'blankbd|blankcd|blankdvd|dvdram|harddisk-external'

“blankbd" = (
deny,
eject
);

“blankcd" = (
deny,
eject
);

“blankdvd" = (
deny,
eject
);

“dvdram" = (
deny,
eject
);

“harddisk-external" = (
deny,
eject
);

If the result does not match the output above and the external writeable media devices have not been approved by the Authorizing Official, this is a finding.

Fix Text (F-53709r802394_fix)
This setting is enforced using the "Restrictions Policy" configuration profile.