Recommendations
1. CCE-37106-2
128 | P a g e CIS Controls:
Version 6
5.1 Minimize And Sparingly Use Administrative Privileges
Minimize administrative privileges and only use administrative accounts when they are required. Implement focused auditing on the use of administrative privileged functions and monitor for anomalous behavior.
Version 7
4.4 Use Unique Passwords
Where multi-factor authentication is not supported (such as local administrator, root, or service accounts), accounts will use passwords that are unique to that system.
4.6 Use of Dedicated Machines For All Administrative Tasks
Ensure administrators use a dedicated machine for all administrative tasks or tasks requiring administrative access. This machine will be segmented from the organization's primary network and not be allowed Internet access. This machine will not be used for reading e-mail, composing documents, or browsing the Internet.
129 | P a g e
2.2.32 (L1) Ensure 'Impersonate a client after authentication' is set to 'Administrators, LOCAL SERVICE, NETWORK SERVICE, SERVICE' and (when the Web Server (IIS) Role with Web Services Role Service is installed) 'IIS_IUSRS' (MS only) (Scored)
Profile Applicability:
Level 1 - Member Server
Description:
The policy setting allows programs that run on behalf of a user to impersonate that user (or another specified account) so that they can act on behalf of the user. If this user right is required for this kind of impersonation, an unauthorized user will not be able to convince a client to connect—for example, by remote procedure call (RPC) or named pipes—to a service that they have created to impersonate that client, which could elevate the unauthorized user's permissions to administrative or system levels.
Services that are started by the Service Control Manager have the built-in Service group added by default to their access tokens. COM servers that are started by the COM
infrastructure and configured to run under a specific account also have the Service group added to their access tokens. As a result, these processes are assigned this user right when they are started.
Also, a user can impersonate an access token if any of the following conditions exist:
The access token that is being impersonated is for this user.
The user, in this logon session, logged on to the network with explicit credentials to create the access token.
The requested level is less than Impersonate, such as Anonymous or Identify.
An attacker with the Impersonate a client after authentication user right could create a service, trick a client to make them connect to the service, and then impersonate that client to elevate the attacker's level of access to that of the client.
The recommended state for this setting is: Administrators, LOCAL SERVICE, NETWORK SERVICE, SERVICE and (when the Web Server (IIS) Role with Web Services Role Service is installed) IIS_IUSRS.
130 | P a g e Note: This user right is considered a "sensitive privilege" for the purposes of auditing.
Note #2: A Member Server with Microsoft SQL Server and its optional "Integration
Services" component installed will require a special exception to this recommendation for additional SQL-generated entries to be granted this user right.
Rationale:
An attacker with the Impersonate a client after authentication user right could create a service, trick a client to make them connect to the service, and then impersonate that client to elevate the attacker's level of access to that of the client.
Audit:
Navigate to the UI Path articulated in the Remediation section and confirm it is set as prescribed.
Remediation:
To establish the recommended configuration via GP, configure the following UI path:
Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment\Impersonate a client after authentication
Impact:
In most cases this configuration will have no impact. If you have installed the Web Server (IIS) Role with Web Services Role Service, you will need to also assign the user right to
IIS_IUSRS. Default Value:
Administrators, LOCAL SERVICE, NETWORK SERVICE, SERVICE.
References:
1. CCE-37106-2
131 | P a g e CIS Controls:
Version 6
5.1 Minimize And Sparingly Use Administrative Privileges
Minimize administrative privileges and only use administrative accounts when they are required. Implement focused auditing on the use of administrative privileged functions and monitor for anomalous behavior.
Version 7
4.4 Use Unique Passwords
Where multi-factor authentication is not supported (such as local administrator, root, or service accounts), accounts will use passwords that are unique to that system.
4.6 Use of Dedicated Machines For All Administrative Tasks
Ensure administrators use a dedicated machine for all administrative tasks or tasks requiring administrative access. This machine will be segmented from the organization's primary network and not be allowed Internet access. This machine will not be used for reading e-mail, composing documents, or browsing the Internet.
132 | P a g e
2.2.33 (L1) Ensure 'Increase scheduling priority' is set to 'Administrators' (Scored)
Profile Applicability:
Level 1 - Domain Controller
Level 1 - Member Server
Description:
This policy setting determines whether users can increase the base priority class of a process. (It is not a privileged operation to increase relative priority within a priority class.) This user right is not required by administrative tools that are supplied with the operating system but might be required by software development tools.
The recommended state for this setting is: Administrators. Rationale:
A user who is assigned this user right could increase the scheduling priority of a process to Real-Time, which would leave little processing time for all other processes and could lead to a DoS condition.
Audit:
Navigate to the UI Path articulated in the Remediation section and confirm it is set as prescribed.
Remediation:
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\Increase scheduling priority
Impact:
None - this is the default behavior.
133 | P a g e Default Value:
On Windows Server 2016 or older: Administrators.
On Windows Server 2019 or newer: Administrators, Window Manager\Window Manager Group.
References:
1. CCE-38326-5