Information
The guest account allows users access to the system without having to create an account or password. Guest users are unable to make setting changes and cannot remotely login to the system. All files, caches, and passwords created by the guest user are deleted upon logging out.
Disabling the guest account mitigates the risk of an untrusted user doing basic reconnaissance and possibly using privilege escalation attacks to take control of the system.
Solution
Run the following command to disable the guest account:
% /usr/bin/sudo /usr/bin/defaults write /Library/Preferences/com.apple.loginwindow GuestEnabled -bool false
Impact:
A guest user can use that access to find out additional information about the system and might be able to use privilege escalation vulnerabilities to establish greater access.
Item Details
Category: ACCESS CONTROL, AUDIT AND ACCOUNTABILITY, IDENTIFICATION AND AUTHENTICATION
References: 800-53|AC-1, 800-53|AC-2, 800-53|AC-2(1), 800-53|AC-3, 800-53|AC-6, 800-53|AC-6(1), 800-53|AC-6(7), 800-53|AU-9(4), 800-53|IA-5(1), CSCv7|4.4
Control ID: 718f5de5680199ff0e138f1e2f69a69f9eab3cca702522e364cd2c3fbc7576bd