Windows Server 2008 introduces new capabilities for Active Directory Domain Services object ownership. These new capabilities do not change the default permissions that the owner of an object is granted; however, they do provide the ability to modify the permissions granted to the owner of an object. The ability to restrict the permissions for the owner on an object is a welcome security enhancement in Windows Server 2008.
Each Active Directory Services object has a security descriptor, which facilitate the ability to secure the object by using permissions. A security descriptor contains all information related to access control for a given object, including:
* The owner of the object
* The primary group of the object (rarely used)
* The discretionary access control list (DACL)
* The system access control list (SACL)
* Control information
By default, the owner of the object is given the WRITE_DAC permission and READ_CONTROL permission. These permissions provide the owner with the ability to change permissions on an object and to read the permissions assigned to an object, respectively.
Issues with Pre-Windows Server 2008 Behavior of Object Ownership
There are a number of issues with the pre-Windows Server 2008 behavior of object ownership. It is important to cover these issues to provide a better understanding of the benefits.
One of the biggest security risks with the pre-Windows Server 2008 behavior of object ownership is that it provides the ability to escalate privileges. Consider the scenario in which you've granted your help desk permission to create user accounts but not the permission to delete user accounts. When a member of the help desk subsequently creates a user account, he becomes the owner of that user account object in the directory. With the pre-Windows Server 2008 behavior of object ownership, they automatically receive the ability to change permissions on the user. If they want to delete the user object, or grant anyone the ability to do so, they can grant the ability to do by modifying the permissions on the user account object.
With the pre-Windows Server 2008 behavior of object ownership, you are limited to taking ownership of an object. As a safeguard, members of the Administrators group can always take ownership of an object, even if the current owner has denied Administrators the permissions to modify the object. However, taking ownership of an object is essentially a reactive step. The pre-Windows Server 2008 behavior of object ownership did not have any means to be proactive.
By default, Windows Server 2008 designates the creator of an object as the owner, which is the same as the pre-Windows Server 2008 behavior. Furthermore, Windows Server 2008 still grants the owner the ability to change permissions of an object and read permissions, which is also consistent with the pre-Windows Server 2008 behavior. However, Windows Server 2008 introduces a new well-known security principal called, Owner Rights, which can be used to restrict the permissions that the owner of an object is granted. In Windows Server 2008, you can add the Owner Rights well-known security principal to the Discretionary Access Control List (DALC) of an object, and control the permissions that assigned to the owner of that object. When you add the Owner Rights well-known security principal to the DALC of an object, you can specify the permissions assigned to the owners of objects. This new capability overrides the default pre-Windows Server 2008 behavior of object ownership.
Each Active Directory Services object has a security descriptor, which facilitate the ability to secure the object by using permissions. A security descriptor contains all information related to access control for a given object, including:
* The owner of the object
* The primary group of the object (rarely used)
* The discretionary access control list (DACL)
* The system access control list (SACL)
* Control information
By default, the owner of the object is given the WRITE_DAC permission and READ_CONTROL permission. These permissions provide the owner with the ability to change permissions on an object and to read the permissions assigned to an object, respectively.
Issues with Pre-Windows Server 2008 Behavior of Object Ownership
There are a number of issues with the pre-Windows Server 2008 behavior of object ownership. It is important to cover these issues to provide a better understanding of the benefits.
One of the biggest security risks with the pre-Windows Server 2008 behavior of object ownership is that it provides the ability to escalate privileges. Consider the scenario in which you've granted your help desk permission to create user accounts but not the permission to delete user accounts. When a member of the help desk subsequently creates a user account, he becomes the owner of that user account object in the directory. With the pre-Windows Server 2008 behavior of object ownership, they automatically receive the ability to change permissions on the user. If they want to delete the user object, or grant anyone the ability to do so, they can grant the ability to do by modifying the permissions on the user account object.
With the pre-Windows Server 2008 behavior of object ownership, you are limited to taking ownership of an object. As a safeguard, members of the Administrators group can always take ownership of an object, even if the current owner has denied Administrators the permissions to modify the object. However, taking ownership of an object is essentially a reactive step. The pre-Windows Server 2008 behavior of object ownership did not have any means to be proactive.
By default, Windows Server 2008 designates the creator of an object as the owner, which is the same as the pre-Windows Server 2008 behavior. Furthermore, Windows Server 2008 still grants the owner the ability to change permissions of an object and read permissions, which is also consistent with the pre-Windows Server 2008 behavior. However, Windows Server 2008 introduces a new well-known security principal called, Owner Rights, which can be used to restrict the permissions that the owner of an object is granted. In Windows Server 2008, you can add the Owner Rights well-known security principal to the Discretionary Access Control List (DALC) of an object, and control the permissions that assigned to the owner of that object. When you add the Owner Rights well-known security principal to the DALC of an object, you can specify the permissions assigned to the owners of objects. This new capability overrides the default pre-Windows Server 2008 behavior of object ownership.
Source: enterpriseitplanet.com
No comments:
Post a Comment