Access to ProfileList Key Restricted with Service Pack 6

ID: Q241042

The information in this article applies to:

Microsoft Windows NT Server version 4.0
Microsoft Windows NT Workstation version 4.0
Microsoft Windows NT Server, Enterprise Edition version 4.0

SYMPTOMS

The following symptoms may occur:

When a user logs on to a computer running Windows NT 4.0, a profile other than the user's assigned profile may be loaded and may run malicious files placed in the StartUp folder. The user may be unaware that the profile substitution has taken place.

A normal domain user can add his or her account to the Domain Administrators group and obtain the permissions of that group by copying the profile to a self-deleting batch file and specifying the path to that file in the ProfileImagePath value in the Administrator's ProfileList key. The next time someone uses the Administrator account and password to log on, the batch file runs and adds that user's profile to the Domain Administrators group.

Users may be able to bypass mandatory profiles.

CAUSE

This behavior occurs in Windows NT 4.0 because the registry key listed below grants the SetValue permission to the Everyone group by default, so that any user (even guests) can edit the information in the ProfileList registry key and its subkeys:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\ProfileList

Editing these keys can be performed locally or remotely, and setting permissions in the Access Control List (ACL) on the Winreg key (HKEY_LOCAL_MACHINE\System) does not limit remote access because the path to the CurrentVersion key is an allowed path and can be edited regardless of the permissions assigned to the Winreg key.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

When you apply Windows NT 4.0 Service Pack 6 (SP6), the default permission on the Everyone group is set to read access only. Also, the process created by Winlogon.exe creates the user's Security Identifier (SID) subkey in the System account, instead of under the CurrentVersion key, and then writes the necessary values to the ProfileList key.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT 4.0 Service Pack 6.

MORE INFORMATION

For more information about making your Windows NT 4.0 installation secure, obtain the "Securing Windows NT Installation" white paper at the following Microsoft Web site:

http://www.microsoft.com/NTServer/security/exec/overview/Secure_NTInstall.asp

Additional query words:

Keywords : kbenv ntsecurity ntsp kbbug4.00 kbfix4.00 NT4SP6Fix
Version : winnt:4.0
Platform : winnt
Issue type : kbbug