Caching of logon credentials must be limited.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-1090	WN08-SO-000024	SV-48023r1_rule	ECSC-1	Low

Description
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 being disconnected from the network or domain controllers being unavailable. Even though the credential cache is well-protected, storing encrypted copies of users' passwords on workstations does not always have the same physical protection required for domain controllers. If a workstation is attacked, an unauthorized individual may isolate the password to a domain user account using a password-cracking program and gain access to the domain.

Description

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 being disconnected from the network or domain controllers being unavailable. Even though the credential cache is well-protected, storing encrypted copies of users' passwords on workstations does not always have the same physical protection required for domain controllers. If a workstation is attacked, an unauthorized individual may isolate the password to a domain user account using a password-cracking program and gain access to the domain.

STIG	Date
Windows 8 / 8.1 Security Technical Implementation Guide	2014-06-27

Details

Check Text ( C-44761r1_chk )
Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.) 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 "4" 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: 4

Check Text ( C-44761r1_chk )

Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.)
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 "4" 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: 4

Fix Text (F-41161r1_fix)
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 "4" logons or less.