2.4.3 Ensure a Custom Message for the Login Screen Is Enabled

Information

An access warning informs the user that the system is reserved for authorized use only, and that the use of the system may be monitored.

An access warning may reduce a casual attacker's tendency to target the system. Access warnings may also aid in the prosecution of an attacker by evincing the attacker's knowledge of the system's private status, acceptable use policy, and authorization requirements.

Solution

Run the following command to enable a custom login screen message:

% /usr/bin/sudo /usr/bin/defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText -string "<custom message>"

Impact:

If users are not informed of their responsibilities, unapproved activities may occur. Users that are not approved for access may take the lack of a warning banner as implied consent to access.

See Also

https://workbench.cisecurity.org/benchmarks/17465