This STIG provides focused security requirements for the AD or Active Directory Domain Services (AD DS) element for Windows Servers operating systems. These requirements apply to the forest and can typically be reviewed once per AD Forest. The separate Active Directory Domain STIG contains domain level requirements. Systems must also be reviewed using the applicable Windows STIG. Comments or proposed revisions to this document should be sent via e-mail to the following address: [email protected]
Changes to the AD schema must be subject to a documented configuration management process.
Poorly planned or implemented changes to the AD schema could cause the applications that rely on AD (such as web and database servers) to operate incorrectly or not all.
Improper changes to the schema could result in changes to AD objects that are incompatible with correct operation of the Windows domain controller and the domain clients. This could cause outages that prevent users from logging on or accessing Windows server resources across multiple hosts.Information Assurance OfficerInformation Assurance ManagerDCPR-1
Anonymous Access to AD forest data above the rootDSE level must be disabled.
For Windows Server 2003 or above, the dsHeuristics option can be configured to override the default restriction on anonymous access to AD data above the rootDSE level. Anonymous access to AD data could provide valuable account or configuration information to an intruder trying to determine the most effective attack strategies.System AdministratorECAN-1, ECCD-1, ECCD-2
The Windows Time Service on the forest root PDC Emulator must be configured to acquire its time from an external time source.
When the Windows Time service is used to synchronize time on client computers (workstations and servers) throughout an AD forest, the forest root domain PDC Emulator is the normal default to provide the authoritative time source for the entire forest. To obtain an accurate time for itself, the forest root domain PDC Emulator acts as a client to an external time source.
If the Windows Time service on the forest root domain PDC Emulator is not configured to acquire the time from a proper source, it may cause time service clients throughout the forest to operate with the inaccurate time setting.
When a Windows computer operates with an inaccurate time setting, access to resources on computers with the accurate time might be denied. This is notably true when Kerberos authentication is utilized. Operation with an inaccurate time setting can reduce the value of audit data and invalidate it as a source of forensic evidence in an incident investigation.Information Assurance Officer
Update access to the directory schema must be restricted to appropriate accounts.
A failure to control update access to the AD Schema object could result in the creation of invalid directory objects and attributes. Applications that rely on AD could fail as a result of invalid formats and values. The presence of invalid directory objects and attributes could cause failures in Windows AD client functions and improper resource access decisions.Information Assurance Officer
Membership to the Schema Admins group must be limited.
The Schema Admins group is a privileged group in a forest root domain. Members of the Schema Admins group can make changes to the schema, which is the framework for the Active Directory forest. Changes to the schema are not frequently required. This group only contains the Built-in Administrator account by default. Additional accounts must only be added when changes to the schema are necessary and then must be removed.