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CERT Coordination Center

Microsoft Services for UNIX Telnet server is vulnerable to denial of service via memory leak

Vulnerability Note VU#994851

Original Release Date: 2001-07-24 | Last Revised: 2001-08-07


The telnet server included in the Microsoft Services for Unix package contains a denial-of-service vulnerability that may cause the system to become unstable or crash.


The telnet server included in the Microsoft Services for Unix (SFU) package contains a memory leak that can lead to excessive resource consumption on affected systems.

This vulnerability affects Microsoft Windows NT 4.0 and Windows 2000 systems that have the SFU package installed. It does not affect the telnet server that ships with Windows NT 4.0 and Windows 2000.


By sending repeated requests to an affected Microsoft telnet server, attackers can consume all available memory resources, resulting in a denial-of-service condition.


Microsoft has released the following patches to address this vulnerability

Windows NT 4.0:
Windows 2000:

Vendor Information


Microsoft Affected

Updated:  August 07, 2001



Vendor Statement

Microsoft has addressed this vulnerability in the following Microsoft Security Bulletin

Vendor Information

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


The CERT/CC has archived Microsoft's announcement of MS01-039 at


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

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This vulnerability was reported to Microsoft by Peter Grundl.

This document was written by Jeffrey P. Lanza and is based on information provided by Microsoft.

Other Information

CVE IDs: CVE-2001-0505
Severity Metric: 4.25
Date Public: 2001-07-24
Date First Published: 2001-07-24
Date Last Updated: 2001-08-07 19:44 UTC
Document Revision: 11

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