Details
Correct date and time settings are required for authentication protocols, file creation, modification dates and log entries.
Note: If your organization has internal time servers, enter them here. Enterprise mobile devices may need to use a mix of internal and external time servers. If multiple servers are required use the Date & Time System Preference with each server separated by a space.
Rationale:
Kerberos may not operate correctly if the time on the Mac is off by more than 5 minutes. This in turn can affect Apple’s single sign-on feature, Active Directory logons, and other features.
Impact:
Apple’s automatic time update solution will enable an NTP server that is not controlled by the Application Firewall. Turning on ‘Set time and date automatically’ allows other computers to connect to set their time and allows for exploit attempts against ntpd. It also allows for more accurate network detection and OS fingerprinting
Current testing shows scanners can easily determine the MAC address and the OS vendor. More extensive OS fingerprinting may be possible.
Solution
Perform the following to enable the date and time to be set automatically:
Graphical Method:
Open System Preferences
Select Date & Time
Verify that Set date and time automatically is selected
Terminal Method:
Run the following commands to enable the date and time setting automatically:
$ sudo systemsetup -setnetworktimeserver
setNetworkTimeServer:
$ sudo systemsetup -setusingnetworktime on
setUsingNetworkTime: On
example:
$ sudo systemsetup -setnetworktimeserver time.apple.com
setNetworkTimeServer: time.apple.com
$ sudo systemsetup -setusingnetworktime on
setUsingNetworkTime: On
Run the following commands if you have not set, or need to set, a new time zone:
$ sudo systemsetup -listtimezones
$ sudo systemsetup -settimezone
example:
$ sudo systemsetup -listtimezones
Time Zones:
Africa/Abidjan
Africa/Accra
Africa/Addis_Ababa
…
Pacific/Wake
Pacific/Wallis
$ sudo systemsetup -settimezone America/New_York
Set TimeZone: America/New_York
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: Audit and Accountability.This control applies to the following type of system Unix.