SecurityvulnsSECURITYVULNS:DOC:289Security Bulletin (MS00-032)
Microsoft Security Bulletin (MS00-032)
Patch and Tool Available for "Protected Store Key Length"
Vulnerability
Originally Posted: June 01, 2000
Summary
Microsoft has released a patch and a tool that eliminate a security
vulnerability in Microsoft(r) Windows(r) 2000. The vulnerability could
make it easier for a malicious user who had complete control over a
Windows 2000 machine to compromise users' sensitive information.
Frequently asked questions regarding this vulnerability
and the patch can be found at
http://www.microsoft.com/technet/security/bulletin/fq00-032.asp
Issue
A Protected Store is provided as part of CryptoAPI, in order to
provide secure storage for sensitive information such as private keys
and certificates. By design, the Protected Store should always encrypt
the information using the strongest cryptography available on the
machine. However, the Windows 2000 implementation uses 40-bit key to
encrypt the Protected Store, even if stronger cryptography is
installed on the machine.
This vulnerability weakens the protection on the Protected Store, but
does not eliminate it. An attacker would need to gain complete
administrative control over the machine that houses the Protected
Store in order to gain access to it, and even then would still need to
mount a brute-force cryptographic attack against it. However,
customers who follow the recommended remediation for this
vulnerability can ensure that such an attack would be significantly
more difficult, if not impossible.
The patch package to eliminate this vulnerability contains a new
version of PBASE.DLL, the module that provides the Protected Store
functionality, and a tool named Keymigrt.exe. Installing PBASE.DLL
will ensure that all future additions to the Protected Store are
encrypted using the strongest cryptography available on the machine.
However, the Keymigrt tool also needs to be run, in order to
re-encrypt all items currently in the Protected Store. We recommend
that system administrators place the Keymigrt tool into users' logon
scripts to ensure that the tool is run the next time they log on.
Affected Software Versions
- Windows 2000 Professional
- Windows 2000 Server
- Windows 2000 Advanced Server
Patch Availability
Note: The patch package contains a patch that needs to be applied to
all affected machines, and a tool that should be run on all affected
machines. The FAQ and Knowledge Base article provide additional
details on their use.
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 MS00-032,
http://www.microsoft.com/technet/security/bulletin/fq00-032.asp - Microsoft Knowledge Base article Q260219 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
Technical Support is available at
http://support.microsoft.com/support/contact/default.asp.
Revisions
- June 01, 2000: Bulletin Created.
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED
"AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL
WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES
WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS
OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION
OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR
CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY
NOT APPLY.
Last updated June 01, 2000
(c) 2000 Microsoft Corporation. All rights reserved. Terms of use.