Home > Articles > Operating Systems, Server > Microsoft Servers

  • Print
  • + Share This
This chapter is from the book

Administrative Delegation

It should be fairly obvious that granting a regular user administrative privileges to a Terminal Server will inevitably result in stability issues. It may not be quite so obvious that the exact same threat exists when legitimate administrators in your domain who are unfamiliar with managing a Terminal Server environment are also granted administrative access to your servers. In this situation, the administrator is just as likely as the regular user (if not more so) to cause server-wide problems based on a change made to the server or an application's configuration.

Historically it has been common to have only one administrative classification in a Windows environment without any further subdivision of privileges into more granular groupings. When someone requires administrative privileges to manage resources in a domain, they are likely added to the Domain Admins group, giving them full administrative privileges that span the entire domain. The result is an environment with multiple administrators with full control over all resources in the domain, yet they may lack the experience to properly administer many of the resources they have full control over. For example, someone skilled in maintenance of Windows file servers may not be qualified to manage Active Directory, a Microsoft SQL Server, or even a Terminal Server. While many argue that it is just "easier" to manage the resources with these privileges, allowing this practice in a Terminal Server environment can introduce a significant threat to your infrastructure's stability.

To help ensure a stable and secure Terminal Server environment, you must not give anyone administrative authority on your servers unless they are qualified to use it. The more Terminal Server administrators you have, the greater the risk of an undesirable change affecting your production environment.

Terminal Server Domain Group Creation

When configuring administrative delegations for your Terminal Server environment, a logical starting point is creation of the four global domain security groups listed in Table 16.1. These are the same groups discussed in Chapter 8 and used when demonstrating group policy object creation in Chapter 15. I review the specific roles of the Terminal Server Operators and User Support groups in more detail in Chapter 22, "Server Operations and Support."

Table 16.1 Terminal Server Administrative Domain Groups

Domain Group Name

Description

Terminal Server Administrators

This domain group is granted full control over the Terminal Server organizational unit and all Terminal Servers in the OU. Members of this group have full authority to manage the Terminal Server environment, and as a result, membership in this group must be tightly managed.

Terminal Server Operators

Users with this privilege level have the authority to monitor the various system functions and perform such tasks as shutting down the server or terminating a process. They don't have the ability to make any system changes or perform application installations.

Terminal Server User Support

Members of this group can perform basic support functions such as shadowing another user's session or logging an active user off. They don't have the ability to restart a server or perform any other server maintenance operations.

Terminal Server Users

This domain group is used to grant basic user access to the production Terminal Servers in the environment. A member of this group can log on to a production Terminal Server and access all the generally available applications. The user has no administrative privileges of any kind.


Delegating Organizational Unit Authority

Once the domain groups are created, you need to delegate administrative privileges for the Terminal Server Administrators group to the Terminal Servers OU. There are two ways you can accomplish this: Either utilize the Delegation of Control wizard, accessible by right-clicking the OU and selecting Delegate Control; or directly update the access control entries from the Security tab found under the properties for the OU, as shown in Figure 16.3. If the Security tab is not visible on the Properties page, you will need to select the Advanced Features option from the View menu.

Figure 16.3Figure 16.3 The Security tab for the Terminal Server organizational unit.

Once the Terminal Server Administrators group has been added, I suggest disabling inheritance of permissions from the OU's parent container. This ensures that permissions must be defined directly against the OU in order to affect delegation of authority, reducing the chances that an undesirable change performed in a parent container will negatively affect this OU's access control list (ACL).

Inheritance is disabled by deselecting the check box labeled "Allow inheritable permissions from parent to propagate to this object." In a Windows 2000 domain, this check box appears on the main Security tab (see Figure 16.3), while in a Windows 2003 domain, you must first click the Advanced button to bring up the dialog box containing this check box. When this option is deselected, you then must make a choice between whether you will keep a copy of inherited permissions or remove all inherited permissions and keep only permissions explicitly defined for the OU.

For this Terminal Server OU, I suggest removing all inherited permissions and keeping only those explicitly defined. In a typical Active Directory environment, your access control list would then look similar to the following:

  • Account Operators

  • Authenticated Users

  • Domain Admins

  • Print Operators

  • ENTERPRISE DOMAIN CONTROLLERS (Windows 2003 Active Directory only)

  • SYSTEM

  • Terminal Server Administrators

Management of this OU should be restricted further by removing the Account Operators object and the Print Operators object from the ACL, leaving Terminal Server Administrators and Domain Admins as the two groups with full authority over the organizational unit. If you have any concerns that a member of the Domain Admins group might inadvertently modify properties of the Terminal Servers OU, you should consider restricting this group's access to the OU as well, either by completely removing the group from the ACL or by modifying the permissions to restrict activities the group can perform.

NOTE

On more than one occasion I've debated the reasons for granting or revoking Domain Admins group access to manage a Terminal Server organizational unit or server. Very often it is argued that the Domain Admins group simply must retain complete control over all elements of a domain, including the Terminal Server environment.

While in theory I agree that this should be the proper configuration, the one condition I feel must be met is that membership in the Domain Admins group be tightly controlled and only those users actually requiring administrative privileges in the domain belong to this group. If this group contains users requiring administrative access to a resource in the domain but not the entire domain itself, I would consider the administrative hierarchy in the domain to be "broken" and would advise against allowing the Domain Admins group to administer the Terminal Server environment. It is simply too risky to give users not familiar with, or responsible for, the Terminal Server environment the ability to modify a Terminal Server's configuration.

Managing Local Group Membership

Now that administrative permissions for the Terminal Server OU have been delegated accordingly, the next step is to create and populate the necessary local groups on each of your Terminal Servers. The idea is to use the local groups on a Terminal Server to assign all the necessary server privileges and then delegate these privileges by populating these groups with the appropriate domain groups. We begin by delegating administrative authority through these local groups and return later in this chapter to assign the appropriate user privileges.

When server security is implemented in this fashion it greatly simplifies administration by introducing a layer of abstraction between the domain and the server. When you know that all security on a server relates back to the local groups, you can verify who has access to what resources simply by viewing local group membership. If domain groups or individual users were directly assigned to the access control lists (ACL) of resources on the server, you would be required to trace back permissions from these resources to the appropriate domain group to ensure that security had not been compromised (intentionally or accidentally).

Before domain groups can be assigned to the local groups on a Terminal Server, we must ensure that these local groups exist. As I discussed in Chapter 8, I typically recommend that the following two additional local groups be created on a Terminal Server to allow for more granular delegation of administrative authority on a Terminal Server:

  • Terminal Server Operators—Used to assign a subset of administrative privileges to those users responsible for managing the day-to-day operations of the Terminal Server. For example, members of this group would have the ability to terminate processes or restart the Terminal Server but would not have the ability to install/remove applications or modify configuration of the server.

  • Terminal Server User Support—Used to assign privileges to those users who would perform typical user support functions. Among other privileges, members of this group would have the ability to shadow other users—something a regular user can't do.

While local groups can be added to a Terminal Server by manually creating them through the Microsoft Management Console (MMC) Computer Management snap-in, I prefer scripting their creation using the Net LocalGroup command. The script is run locally on a Terminal Server during the initial configuration phase to create the desired local groups. The following code sample demonstrates how these two groups could be created using a script:

@ECHO OFF
REM Create the desired local groups on the Terminal Server
net localgroup "Terminal Server Operators" /add
net localgroup "Terminal Server User Support" /add

Once the necessary local groups have been created, we are ready to assign the appropriate domain groups. The most common means of assigning a domain group to a local server group is directly through the MMC Computer Management snap-in, as shown in Figure 16.4. While easy enough, this method is still prone to error when the task must be duplicated across a number of Terminal Servers. Another option to consider is scripting the local group assignment, similar to what I suggested for creation of the local groups. Unfortunately this is really effective only if the local group memberships will remain static. In a production Terminal Server environment, it is likely that local group membership assignments will change over time. In a large Terminal Server environment it would not be practical to adjust and rerun a membership script on all servers. As a result, an alternative allowing more dynamic control over local group membership is necessary.

The preferred method of managing local group membership is through a group policy object (GPO) in an Active Directory domain. Through a single GPO we can define a local group membership standard that is consistent across all Terminal Servers in the domain. This method not only allows for consistent definition of the local group members but also provides dynamic control over the membership we are looking for.

Figure 16.4Figure 16.4 Assigning domain groups to a local group through the Local Users and Groups container.

To demonstrate how this is done, I use the "Terminal Server Machine Policy" created in Chapter 15. This GPO contains all the base computer configuration settings for all the Terminal Servers in the OU. There are no user configuration options defined in this GPO. The local group membership is controlled from within the Restricted Groups policy, located under Computer Configuration\Windows Settings\Security Settings.

Managing the local group membership is a two-stage process. First the local groups that will be populated are added to the Restricted Groups policy, and then the desired domain members are added to each of these groups. The local groups are added to the policy by right-clicking Restricted Groups and selecting the Add Group menu option. The dialog box shown in Figure 16.5 opens, where you can enter the desired local group name.

Figure 16.5Figure 16.5 Accessing the "Terminal Server Machine Policy."

Note that there is no validation performed on any groups that you add to the Restricted Groups policy. If the group name you provide does not exist on the Terminal Server, the group name is simply ignored and is not automatically created by the GPO.

Typically I define the following local groups within the Restricted Groups policy:

  • Administrators—Members of this group will have full administrative control over the Terminal Server. Because of this, access should be very tightly controlled.

  • Terminal Server Operators—This group name is used to assign a subset of administrative privileges to those users responsible for managing the day-to-day operations of the Terminal Server.

  • Terminal Server User Support—Those users responsible for performing typical user support functions such as shadowing or session logoffs would be members of this group.

  • Remote Desktop Users (Windows Server 2003 only)—To remotely log on to a Windows 2003 Terminal Server, a user must be a member of this existing local server group.

  • Users—All regular users who require access to run one or more applications on the Terminal Server are assigned to this local group.

  • Power Users, Guests—These two groups are included in the Restricted Groups policy to ensure that no users are members of either of them.

  • Anonymous (MetaFrame servers only)—When MetaFrame is installed on a Terminal Server, it adds support for anonymous logons through the special Anonymous group. Just as with the Power Users and Guests groups, this group is included in the Restricted Groups policy to ensure that no users belong to this group. Of course, if your MetaFrame server will allow this type of support you will need to omit this entry from the GPO.

TIP

TIP: If you are running Active Directory Users and Computers directly off a domain controller, then browsing for the group name to add to the Restricted Groups policy will present you with only the available domain groups. To be able to browse for local groups on a Terminal Server, you need to run Active Directory Users and Computers directly from the member Terminal Server. From a domain controller, you can still type in the desired local Terminal Server group name; you're just unable to browse for it using the GUI.

After all the local groups have been defined within the Restricted Groups policy, the next step is to assign the appropriate domain groups to these local groups. This is done by right-clicking the desired local group in the right-hand pane and selecting the Security option from the pull-down menu. The Configure Membership dialog box appears, as shown in Figure 16.6. By default this group contains no members and belongs to no other group. If these options are left as-is, then when the policy is applied to the server, all members who may have been manually added to the local group are removed. Domain groups are added by clicking the Add button on the upper half of the dialog box for the Members of This Group option. Since we're configuring only local groups on the Terminal Server, there is no need to modify the lower portion of the dialog box, labeled This Group Is a Member Of.

Figure 16.6Figure 16.6 The Configure Membership dialog box for a listed Restricted Group.

Once the Add button has been clicked, an Add Members dialog box appears. This dialog box lets you type in the name of the domain group or click the Browse button to find the desired group within the domain. Multiple groups can be entered at once by separating them with a semicolon. When manually typing in the group name, be sure to precede it with the domain name and a backslash. For example, to add the domain group Terminal Server Operators of the domain called PRODUCTION, you would type the following:

PRODUCTION\Terminal Server Operators

When you have completed entering the desired domain groups for a given local group, click OK to close the Configure Membership dialog box. Each of the local groups listed in the Restricted Groups policy now appears in the Members column when the Details view is active (see Figure 16.7, which shows the defined groups in a Windows 2000 domain). When the GPO is applied to all servers in the Terminal Server OU, all the listed local groups are updated with the corresponding domain groups. As I mentioned, groups with no explicit memberships will have any existing memberships removed on the affected Terminal Servers.

Figure 16.7Figure 16.7 Viewing local groups in Restricted Groups.

Table 16.2 summarizes my suggestions for local group membership in a Terminal Server Restricted Groups policy. The domain groups listed in this table were discussed in the "Terminal Server Domain Group Creation" section, earlier in this chapter.

Table 16.2 Terminal Server Restricted Group Membership Suggestions

Local Terminal Server Group Name

Domain Group Membership Suggestion

Administrators

Terminal Server Administrators—Only administrators will have full authority on a Terminal Server.

Anonymous

Leaving this group empty ensures that the local group contains no user accounts.

Guests

Leave this group empty.

Power Users

Leave this group empty.

Remote Desktop Users (Windows Server 2003 only)

Terminal Server Users, Terminal Server Administrators—For users to be able to log on via a Terminal Server session (RDP or ICA), they must belong to this group. This applies to a Windows Server 2003 Terminal Server only.

Terminal Server Operators

Terminal Server Operators.

Terminal Server User Support

Terminal Server User Support.

Users

Terminal Server Users—Users with standard access to a Terminal Server and its applications.


NOTE

I've found that managing security exclusively through the local security groups on a Terminal Server is also helpful when migrating a Terminal Server from one domain to another. I was once involved in a project where a number of Terminal Servers were being tested in a test domain that was an exact duplicate of production but completely segregated from the production domain. Once the testing and validation had been completed, the Terminal Servers were removed from one domain and added to the other. Once the Terminal Servers were in the production domain, the only change required was to assign the appropriate domain groups to the local groups on the Terminal Server. All other aspects of the servers remained unchanged, helping ensure that the configuration tested matched the final production deployment as much as possible.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020