As discussed previously, the Authentication ID parameter, which is the key link between an access token and the logon session that it represents, contains a 64 bit LUID logon ID which identifies the origin logon session that this access token is associated with.
Note also that it is possible to infer a number of other conclusions about the state of this token, e. Whenever a thread attempts to access a securable object managed by the Windows kernel, such as a process, thread, handle, semaphore, token, etc.
To perform this check, Windows needs three pieces of information 2 :. Hence, Windows will first check the token associated with the calling thread and look at the authorization attributes cached in it e. Secondly, Windows will look at the desired access requested by the thread. In the Windows security model you must state your intentions upfront; for performance reasons an access check only occurs once and no further checks are performed on any additional handle operations unless a user attempts to perform an action that the handle did not have rights to, e.
Thirdly, Windows will retrieve the security descriptor for the target object. Based on these three sources of information, Windows can give a boolean answer to whether a principal has access to a given object.
For example, if a token has the SeDebugPrivilege privilege enabled, the Windows kernel will skip the DACL checks for any process and thread objects hence why it is so powerful. The operating system performs this action by using the newly minted access token to spawn explorer. This function takes a handle to a token and spawns a new process as the user specified in the token i. Typically, every process created by the user is a child of the shell process i.
As each process has its own local copy of an access token, a process can modify the volatile security settings stored in its copy without affecting other processes. For example, a browser such as Chrome may want to create a restricted version of its access token in order to effectively sandbox the application in the event an attacker is able to exploit the browser and obtain arbitrary code execution on the compromised machine.
As a consequence of the sandbox, any actions performed by the attacker will be restricted and help prevent further damage. The key point is that Chrome can modify its local copy of the token without affecting other applications. Alternatively, a new restricted copy of a specified access token can be created with CreateRestrictedToken.
As an example, the relevant functionality in the chromium source code can be found here. This is so important because, as discussed above, access tokens are the core component of the Windows security model and so by being able to change the information cached in them, a developer can limit what securable objects a token can touch and hence restrict its access across a system.
Having covered local authentication and access control, what happens under the hood when a user needs to access some resource located across the network? For example, a user could attempt to view the available shares on another host by running the following command:. The token would be meaningless as it does not correspond to a valid logon session on the remote host.
Furthermore, this authentication mechanism would be an obvious target for replay attacks. In this case, the user needs to re-authenticate and establish a new logon session on the remote machine assuming the user has access. For an interactive logon and actually all other logon types like service, batch, etc.
As a consequence, access tokens which link back to these types of logon sessions can authenticate to remote hosts and Windows will automatically authenticate on the users behalf whenever a network resource is accessed by a thread or process. A security descriptor is often placed on a high part of a directory path or process chain and the items below the secured object inherit the descriptors and become secured themselves.
This simplifies the process for the user since he only needs to secure one thing to create a secured area. Since the term is so vague, it is often used to describe file and process securing methods on other systems that use different methods. While securable objects and common objects are different, the term is unrelated to the actual difference.
The system uses the term to denote anything that it can or may access and everything it has accessed — so nearly every non-fixed bit of information on the system is an object. These objects could be on the user side, such as a file or folder full of files, or they could be a system side object, such as a running process or registry entry.
You can get the list of all protected groups in an Active Directory Domain by running the following Powershell command:. The same is applicable on protected user accounts and you can the following Powershell command to get the list:. Doing this exclusion could be done by updating dsHeuristic flag.
This can be calculated by combining the Binary values of each group to exclude and converting the sum to Hexadecimal. Once converted to Hexadecimal, it will be 9. If you set 9 as the value of dsHeuristics flag, both groups will be excluded.
Yes, you can enable the inheritance of permissions from the parent object on AdminSDHolder container to allow the propagation of parent ACLs on protected groups and their members. However, this is highly not recommended. Office Office Exchange Server.
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