Article ID: 282806
Article Last Modified on 1/29/2007
APPLIES TO
- Microsoft Windows 2000 Service Pack 1
- Microsoft Windows 2000 Service Pack 2
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Service Pack 2
- Microsoft Windows 2000 Service Pack 1
This article was previously published under Q282806
SYMPTOMS
A denial-of-service vulnerability exists in the Windows 2000 Telnet service that can prevent an idle Telnet session from timing out. By starting as many sessions as the server could accommodate, and letting them idle in a particular way, an attacker could prevent other users from establishing Telnet sessions.
Mitigating Factors
- It would not be necessary to reboot the server to recover from this vulnerability. At worst, the Telnet service would need to be restarted.
- This vulnerability cannot be used to gain additional privileges on the computer; it is a denial-of-service vulnerability only.
RESOLUTION
To resolve this problem, either obtain Windows 2000 Service Pack 3 or Windows 2000 Security Rollup Package 1 (SRP1). To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows 2000 Service Pack
For additional information about SRP1, click the article number below to view the article in the Microsoft Knowledge Base:
311401 Windows 2000 Security Rollup Package 1 (SRP1), January 2002
The following file is available for download from the Microsoft Download Center:
![[GRAPHIC: Download]](/wiki/index.php?title=File:Download.gif){kind=small}
Release Date: June 7, 2001
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.
The English version of this fix should have the following file attributes or later:
Date Time Version Size File name
-----------------------------------------------------
05/24/2001 04:14p 5.0.33667.1 186,128 Tlntsvr.exe
STATUS
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Windows 2000. This problem was first corrected in Windows 2000 Service Pack 3.
MORE INFORMATION
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:
265173 The Datacenter Program and Windows 2000 Datacenter Server Product
For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:
296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot
For additional information about what is fixed by this patch, click the article number below to view the article in the Microsoft Knowledge Base:
300855 Windows 2000 Telnet Security Rollup
For more information about this vulnerability, see the following Microsoft Web site:
Additional query words: security_patch DoS kbWin2000srp1
Keywords: kbbug kbfix kbwin2000presp3fix kbsecvulnerability kbwin2000sp3fix kbsecurity kbsecdos kbsecbulletin kbsechack KB282806
