IgNiTeD SoUL

A good security step to take to prevent hackers and others from making unauthorized changes to a system’s registry is to prevent remote access to a system’s registry. When a user attempts to connect to a registry remotely, Windows Server 2008 checks the ACL for the following registry key:

HKLM\System\ControlSet001\Control\SecurePipeServers\winreg

If this key is missing, all users can access the registry subject to the permissions assigned to individual keys. If the key exists, Windows Server 2008 checks the permissions on the key to determine whether or not the remote user can gain access to the registry (and levels of access). Individual keys then determine what these remote users can do with a given key. Therefore, winreg is the first line of defense, and individual key ACLs are the second line of defense. If you want to prevent all remote access to the registry, make sure you set the permissions on the winreg key accordingly.