Microsoft Security Bulletin (MS00-099)
   
   Patch Available for Directory Service Restore Mode Password
   Vulnerability
   
   Originally posted: December 20, 2000
   
Summary

   Microsoft has released a patch that eliminates a security
   vulnerability affecting Microsoft® Windows® 2000 domain controllers.
   The vulnerability could allow a malicious user with physical access to
   a domain controller to install malicious software on it.
   
   Frequently asked questions regarding this vulnerability and the patch
   can be found at
   http://www.microsoft.com/technet/security/bulletin/fq00-099.asp
   
Issue

   Windows 2000 provides several special operating modes that can be
   chosen at boot time in order to allow the administrator to
   troubleshoot and restore a machine with a damaged configuration. One
   of these, Directory Service Restore Mode, is designed to allow the
   Active Directory to be repaired and restored on a domain controller. A
   password is required in order to operate the system in this mode.
   However, if the Configure Your Server tool was used when the machine
   was originally promoted to domain controller, that password would be
   blank. This could enable a malicious user to log onto the machine in
   Directory Service Restore Mode. Once logged on, the malicious user
   could alter system components or install bogus ones that would execute
   when a bona fide administrator subsequently logged onto the machine.
   
   There are three significant mitigating factors associated with this
   vulnerability:
     * The malicious user would need physical access to the machine in
       order to log into it in Directory Service Restore Mode. However,
       security best practices strongly recommend against ever giving
       unprivileged users physical access to critical servers like domain
       controllers. Customers who have followed this guidance would not
       be affected by the vulnerability.
     * The vulnerability only occurs if the Configure Your Server tool
       was used to promote the server to domain controller. If the
       DCPROMO tool was used, the machine could not be affected by the
       vulnerability.
     * The Configure Your Server tool can only be run on the first domain
       controller in a forest. As a result, no other servers could be
       affected by the vulnerability.
       
   A second troubleshooting mode also is affected. When the Directory
   Service Restore Mode password is set, the password for the Recovery
   Console is automatically synchronized with it. As a result, machines
   affected by this vulnerability would have a blank password for both
   the Directory Service Restore Mode and the Recovery Console. However,
   the scope of the vulnerability is unchanged by the involvement of the
   Recovery Console, for better or worse.
   
Affected Software Versions

     * Microsoft Windows 2000 Server
     * Microsoft Windows 2000 Advanced Server
       
   Note: Windows 2000 workstations are unaffected by this vulnerability.
   
Patch Availability

     * The patch has been temporarily removed, but will be re-posted
       shortly
       
   Note: On Windows 2000 Server and Advanced Server systems, this patch
   can be installed atop either the Gold version or Service Pack 1. It
   will be included in Windows Server and Advanced Server, Service Pack
   2.
   
   Note Additional security patches are available at the Microsoft
   Download Center 
   
More Information

   Please see the following references for more information related to
   this issue.
     * Frequently Asked Questions: Microsoft Security Bulletin MS00-099,
       http://www.microsoft.com/technet/security/bulletin/fq00-099.asp
     * Microsoft Knowledge Base article Q271641 discusses this issue and
       will be available soon.
     * Microsoft TechNet Security web site,
       http://www.microsoft.com/technet/security/default.asp
       
Obtaining Support on this Issue

   This is a fully supported patch. Information on contacting Microsoft
   Product Support Services is available at
   http://support.microsoft.com/support/contact/default.asp.
   
Acknowledgments

   Microsoft thanks  John Sherriff of the Wool Research Organization of
   New Zealand for reporting this issue to us and working with us to
   protect customers.
   
Revisions

     * December 20, 2000: Bulletin Created.
       
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     Last updated December 12, 2000
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