SYMPTOMS
An information-disclosure vulnerability exists in the Windows 2000 Telnet service that can make it easier for an attacker to exploit an incorrectly configured network. It would not give an attacker a way to do anything that the attacker could not already do. In the worst case, the vulnerability could assist an attacker in gaining access to a domain account.
This vulnerability has a number of significant restrictions:
- The attacker would need to know the correct password for the account. The most likely account to be affected--the Guest account--is disabled by default.
- The vulnerability could only be exploited if the system administrator had made the Telnet server a domain member.
RESOLUTION
To resolve this problem, either obtain the hotfix referenced in this section or Windows 2000 Security Rollup Package 1 (SRP1). 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
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that you determine are at risk of attack. Evaluate your computer's physical accessibility, network and Internet connectivity, and other factors to determine the degree of risk to your computer. See the associated
Microsoft Security Bulletin to help determine the degree of risk. This fix may receive additional testing. If your computer is sufficiently at risk, Microsoft recommends that you apply this fix now. Otherwise, wait for the next Windows 2000 service pack that contains this fix.
To resolve this problem immediately, download the fix by following the instructions later in this article or contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:
NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
The following file is available for download from the Microsoft Download Center:
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
