Restrict access for null sessions anonymous user access

This policy setting enables or disables the restriction of anonymous access to only those shared folders and pipes that are named in the Network access: Named pipes that can be accessed anonymously and Network access: Shares that can be accessed anonymously settings. This registry value toggles null session shared folders on or off to control whether the Server service restricts unauthenticated clients' access to named resources.

Null sessions are a weakness that can be exploited through the various shared folders on the devices in your environment. The following table lists the actual and effective default values for this policy. Changes to this policy become effective without a device restart when they are saved locally or distributed through Group Policy.

This section describes how an attacker might exploit a feature or its configuration, how to implement the countermeasure, and the possible negative consequences of countermeasure implementation. Null sessions are a weakness that can be exploited through shared folders including the default shared folders on devices in your environment. You can enable this policy setting to restrict null-session access for unauthenticated users to all server pipes and shared folders except those that are listed in the NullSessionPipes and NullSessionShares entries.

Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. You can enable this policy setting to restrict null-session access for unauthenticated users to all server pipes and shared folders except those that are listed in the NullSessionPipes and NullSessionShares entries.

If you choose to enable this setting, and you are supporting Windows NT 4. In operating systems earlier than Windows Server with Service Pack 1 SP1 , these named pipes were allowed anonymous access by default.

In later operating systems, these pipes must be explicitly added if needed. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. In this article.