FIX: DCOMCNFG NT 4.0 SP4 Does Not Write .exe Name under HKCR\APPID

ID: Q216051

The information in this article applies to:

Microsoft Windows NT 4.0

SYMPTOMS

Clients get an Access Denied error although the access is granted to the client using DCOMCNFG.

CAUSE

When access permissions for a DCOM server are configured using DCOMCNFG, the .exe name should be mapped to an AppID under HKEY_CLASSES_ROOT\APPID; however, it does not do this in Windows NT 4.0 Service Pack 4 (SP4).

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

http://www.microsoft.com/Windows/ServicePacks/

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

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

AccessPermissions work as follows:

If the server calls CoInitializeSecurity, the ACL comes from the API.

If the server does not call CoInitializeSecurity, then if there is an AccessPermissions key under the server's AppID GUID, the ACL comes from this. There must be a mapping of the .exe name to the AppID in the registry. For example:
```
REGEDIT4

      [HKEY_CLASSES_ROOT\AppID\sserver.exe]
      @="Simple Object Server"
      "AppID"="{5E9DDEC7-5767-11CF-BEAB-00AA006C3606}"

      [HKEY_CLASSES_ROOT\AppID\{5E9DDEC7-5767-11CF-BEAB-00AA006C3606}]
      @="Simple Object Server"

      "AccessPermission"=hex:01... 
```
This is how COM maps the AppID from the server process's module name.

If there is no AccessPermissions key under server's AppID, then if there is a DefaultAccessPermission key under HKLM\Software\Microsoft\Ole, the ACL comes from here.

If there is no DefaultAccessPermission key under HKLM\Software\Microsoft\Ole, the server principal and SYSTEM are allowed to call the server; that is, if the server is running as a_domain\a_user, a client running as a_domain\a_user can call it.

Additional query words: kbbuglist

Keywords : kbCOMt kbDCOM kbNTOS400 kbNTOS400sp4bug kbGrpCom kbDSupport kbNTOS400sp5fix
Version : winnt:4.0
Platform : winnt
Issue type : kbbug