Vulnerability Discussion

If the system does not require TFTP support, it is nonessential and must be disabled.

The information system must be configured to provide only essential capabilities. Disabling TFTP helps prevent the unauthorized connection of devices and unauthorized transfer of information.

Note: TFTP service is disabled at startup by default.

Satisfies: SRG-OS-000074-GPOS-00042, SRG-OS-000080-GPOS-00048

Check

Verify the macOS system is configured to disable TFTP service with the following command:

result="FAIL"
enabled=$(/bin/launchctl print-disabled system | /usr/bin/grep '"com.apple.tftpd" => enabled')
running=$(/bin/launchctl print system/com.apple.tftpd 2>/dev/null)

if [[ -z "$running" ]] && [[ -z "$enabled" ]]; then
result="PASS"
elif [[ -n "$running" ]]; then
result=result+" RUNNING"
elif [[ -n "$enabled" ]]; then
result=result+" ENABLED"
fi
echo $result

If the result is not "PASS", this is a finding.

Fix

Configure the macOS system to disable TFTP service with the following commands:

/bin/launchctl bootout system/com.apple.tftpd
/bin/launchctl disable system/com.apple.tftpd

The system may need a restart for the update to take effect.