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

Vulnerability Note VU#570330

Original Release Date: 2001-08-15 | Last Revised: 2001-08-15


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.

Vendor Information

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Updated:  August 15, 2001



Vendor Statement


Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

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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: CVE-2000-1149
Severity Metric: 16.88
Date Public: 2000-11-08
Date First Published: 2001-08-15
Date Last Updated: 2001-08-15 04:29 UTC
Document Revision: 5

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