Vulnerability Note VU#570330

MS Windows NT Terminal Server 4.0 buffer overflow in regapi.dll allows remote code execution or DoS

Original Release date: 15 Aug 2001 | Last revised: 15 Aug 2001


Microsoft Windows NT 4.0 Terminal Server contains a buffer overflow that could allow an intruder to execute arbitrary code with the privileges of an administrator.


There is a buffer overflow in the code that processes the username (specifically in RegAPI.DLL) in Microsoft Windows NT 4.0 Terminal Server. This allows an intruder to submit a specially crafted username in such a way as to cause Terminal Server to execute code of the intruder's choosing. The intruder does not need to have a valid username or password; anyone with access to port 3389/TCP can exploit this vulnerability.


Intruders can execute arbitrary code with the privileges of a logged in administrator. Additionally, an intruder who can log in locally can cause Terminal Server to crash.


Apply a patch as described in

You may also with to block access to port 3389/TCP to reduce your exposure to this vulnerability. This does not eliminate the vulnerability, but it does reduce the number of people who can exploit it.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
MicrosoftAffected-15 Aug 2001
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was discovered by Bruno Acselrad of CORE SDI S.A., Buenos Aires, Argentina.

This document was written by Shawn V. Hernan.

Other Information

  • CVE IDs: CAN-2000-1149
  • Date Public: 08 Nov 2000
  • Date First Published: 15 Aug 2001
  • Date Last Updated: 15 Aug 2001
  • Severity Metric: 16.87
  • Document Revision: 5


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