Title

Caching of logon credentials is not limited. (Cat III impact)

Discussion

The default Windows configuration caches the last logon credentials for users who log on interactively to a system. This feature is provided for system availability reasons such as the user’s machine is disconnected from the network or domain controllers are not available. Even though the credential cache is well-protected, storing encrypted copies of users passwords on systems do not always have the same physical protection required for domain controllers. If a system is attacked, the unauthorized individual may isolate the password to a domain user account using a password-cracking program, and gain access to the domain.

Check Content

Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. Navigate to Local Policies -> Security Options. If the value for “Interactive Logon: Number of previous logons to cache (in case Domain Controller is unavailable)” is not set to “2” logons or less, this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ Value Name: CachedLogonsCount Value Type: REG_SZ Value: 2

Fix Text

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “Interactive Logon: Number of previous logons to cache (in case Domain Controller is not available)” to “2” logons or less.

Additional Identifiers

Rule ID: SV-1090r2_rule

Vulnerability ID: V-1090

Group Title: Caching of logon credentials

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