Information
Ensure 'Interactive logon: Number of previous logons to cache (in case domain controller is not available)' is set to '4 or fewer logon(s)' (MS only)
This policy setting determines whether a user can log on to a Windows domain using cached account information.
Logon information for domain accounts can be cached locally to allow users to log on even if a Domain Controller cannot be contacted.
This policy setting determines the number of unique users for whom logon information is cached locally.
If this value is set to 0, the logon cache feature is disabled.
An attacker who is able to access the file system of the server could locate this cached information and use a brute force attack to determine user passwords.
The recommended state for this setting is: '4 or fewer logon(s)'.
Rationale:
The number that is assigned to this policy setting indicates the number of users whose logon information the computer will cache locally.
If the number is set to 4, then the computer caches logon information for 4 users.
When a 5th user logs on to the computer, the server overwrites the oldest cached logon session.
Users who access the computer console will have their logon credentials cached on that computer.
An attacker who is able to access the file system of the computer could locate this cached information and use a brute force attack to attempt to determine user passwords.
To mitigate this type of attack, Windows encrypts the information and obscures its physical location.
Solution
To establish the recommended configuration via GP, set the following UI path to '4 or fewer logon(s)':
Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\Security Options\Interactive logon: Number of previous logons to cache (in case domain controller is not available)
Impact:
Users will be unable to log on to any computers if there is no Domain Controller available to authenticate them.
Organizations may want to configure this value to 2 for end-user computers, especially for mobile users.
A configuration value of 2 means that the user's logon information will still be in the cache, even if a member of the IT department has recently logged on to their computer to perform system maintenance.
This method allows users to log on to their computers when they are not connected to the organization's network.