2.2.5 Ensure 'Add workstations to domain' is set to 'Administrators' (DC only)

Information

This policy setting specifies which users can add computer workstations to the domain. For this policy setting to take effect, it must be assigned to the user as part of the Default Domain Controller Policy for the domain. A user who has been assigned this right can add up to 10 workstations to the domain. Users who have been assigned the

Create Computer Objects

permission for an OU or the Computers container in Active Directory can add an unlimited number of computers to the domain, regardless of whether or not they have been assigned the Add workstations to domain user right.

In Windows-based networks, the term security principal is defined as a user, group, or computer that is automatically assigned a security identifier to control access to resources. In an Active Directory domain, each computer account is a full security principal with the ability to authenticate and access domain resources. However, some organizations may want to limit the number of computers in an Active Directory environment so that they can consistently track, build, and manage the computers. If users are allowed to add computers to the domain, tracking and management efforts would be hampered. Also, users could perform activities that are more difficult to trace because of their ability to create additional unauthorized domain computers.

The recommended state for this setting is: Administrators

The Add workstations to domain user right presents a moderate vulnerability. Users with this right could add a computer to the domain that is configured in a way that violates organizational security policies. For example, if your organization does not want its users to have administrative privileges on their computers, a user could (re-)install Windows on his or her computer and then add the computer to the domain. The user would know the password for the local Administrator account, and could log on with that account and then add his or her domain account to the local Administrators group.

Solution

To establish the recommended configuration via GP, set the following UI path to Administrators :

Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment\Add workstations to domain

Impact:

For organizations that have never allowed users to set up their own computers and add them to the domain, this countermeasure will have no impact. For those that have allowed some or all users to configure their own computers, this countermeasure will force the organization to establish a formal process for these procedures going forward. It will not affect existing domain computers unless they are removed from and re-added to the domain.

See Also

https://workbench.cisecurity.org/benchmarks/15301