Information
Allowing guests to connect to shared folders enables users to access selected shared folders and their contents from different computers on a network.
Rationale:
Not allowing guests to connect to shared folders mitigates the risk of an untrusted user doing basic reconnaissance and possibly use privilege escalation attacks to take control of the system.
Impact:
Unauthorized users could access shared files on the system.
Solution
Perform the following to implement the prescribed state:
Open System Preferences
Select Users & Groups
Select Guest User
Uncheck Allow guests to connect to shared folders
Alternatively:
For AFP sharing:
Run the following command in Terminal:
sudo defaults write /Library/Preferences/com.apple.AppleFileServer guestAccess -bool no
For SMB sharing:
Run the following command in Terminal:
sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.smb.server AllowGuestAccess -bool no