Microsoft Security Bulletin (MS00-032) - Patch and Tool Available for "Protected Store Key Length" vulnerability. This vulnerability makes it easier for a malicious user who has complete control over a Windows 2000 machine to compromise users private keys and certificates. Protected Shares in Windows 2000 are only encrypted with 40 bits, while they are to be protected with the strongest available encryption. Microsoft FAQ on this issue available here.
6cd5ac9e35ce150759d578536613c72e94ab1466a4d3677ca0a93b5ed09feddd
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Updated to correct a packaging and regression problem with the
original patch.
Microsoft Security Bulletin (MS00-032)
- --------------------------------------
Patch and Tool Available for "Protected Store Key Length"
Vulnerability
Originally Posted: June 01, 2000
Updated: July 26, 2000
Summary
=======
On June 01, 2000, Microsoft released the original version of this
bulletin. However, an error was subsequently discovered in the patch,
and on July 26, 2000, Microsoft released a corrected version.
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 PSBASE.DLL, the module that provides the Protected Store
functionality, and a tool named Keymigrt.exe. Installing PSBASE.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
==================
http://www.microsoft.com/Downloads/Release.asp?ReleaseID=23332
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 (KB) article Q260219,
http://www.microsoft.com/technet/support/kb.asp?ID=260219
- 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.
- July 26, 2000: Updated to correct a regression and
packaging problem with the original patch.
- ---------------------------------------------------------------------
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THE FOREGOING LIMITATION MAY NOT APPLY.
Last updated July 26, 2000
© 2000 Microsoft Corporation. All rights reserved. Terms of use.
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