MS01-051: Patch Available for Telnet Logging Vulnerability (286043)



The information in this article applies to:

  • Microsoft Internet Explorer 5.5 for Windows NT 4.0 SP 1
  • Microsoft Internet Explorer 5.5 for Windows NT 4.0 SP 2
  • Microsoft Internet Explorer 5.01 for Windows NT 4.0 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 98 Second Edition SP 1
  • Microsoft Internet Explorer 5.5 for Windows 98 Second Edition SP 2
  • Microsoft Internet Explorer 5.01 for Windows 98 Second Edition SP 1
  • Microsoft Internet Explorer 5.5 for Windows 98 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 98 SP 2
  • Microsoft Internet Explorer 5.01 for Windows 98 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 95 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 95 SP 2
  • Microsoft Internet Explorer 5.01 for Windows 95 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 2000 SP 1
  • Microsoft Internet Explorer 5.5 for Windows 2000 SP 2
  • Microsoft Internet Explorer 5.01 for Windows 2000 SP 1
  • Microsoft Internet Explorer version 6 for Windows XP
  • Microsoft Internet Explorer version 6 for Windows 2000
  • Microsoft Internet Explorer version 6 for Windows NT 4.0
  • Microsoft Internet Explorer version 6 for Windows Millennium Edition
  • Microsoft Internet Explorer version 6 for Windows 98 Second Edition
  • Microsoft Internet Explorer version 6 for Windows 98

This article was previously published under Q286043

SYMPTOMS

A patch is available for a Telnet logging vulnerability. By design, you can start Telnet sessions by using Internet Explorer; however, a vulnerability exists because, when you start Telnet sessions by using Internet Explorer, Internet Explorer starts Telnet by using any command-line options that the Web site specifies.

This vulnerability exists only when you use the version of the Telnet client that is installed with Services for UNIX 2.0 on computers that are running either Windows NT 4.0 or Windows 2000. The version of the Telnet client in Services for UNIX 2.0 provides an option to create a verbatim transcript of a Telnet session. A malicious user can start a session by using the logging option, and then stream a program file to the user's computer in a location that can cause the file to be run automatically the next time that the user starts the computer. This vulnerability is with Internet Explorer, which should not allow Telnet to be started remotely with command-line arguments.

The vulnerability can be exploited only if a particular version of the Telnet utility is installed on the computer. This version is only available as part of a separate add-on package that can be installed only on computers that are running either Windows NT 4.0 or Windows 2000. This version of Telnet is not included with any operating system.

RESOLUTION

Internet Explorer 6

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 Internet Explorer 6 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 "Security Update, December 13, 2001" patch is superseded by the following patch:

316059 MS02-005: February 11, 2002, Cumulative Patch for Internet Explorer

The "Security Update, December 13, 2001" patch is available at the following Microsoft Web site:

Internet Explorer 5.5

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 Internet Explorer 5.5 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 "Security Update, December 13, 2001" patch is superseded by the following patch:

316059 MS02-005: February 11, 2002, Cumulative Patch for Internet Explorer

The "Security Update, December 13, 2001" patch is available at the following Microsoft Web site:

Internet Explorer 5.01

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 Internet Explorer 5.01 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 "Security Update, October 10, 2001" patch is superseded by the following patches:

316059 MS02-005: February 11, 2002, Cumulative Patch for Internet Explorer

311401 Windows 2000 Security Rollup Package 1 (SRP1), January 2002

The "Security Update, October 10, 2001" patch is available at the following Microsoft Web site:

Internet Explorer 5.01 for Windows 2000

To resolve this problem, obtain the latest service pack for Internet Explorer 5.01 for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

267954 How to Obtain the Latest Internet Explorer 5.01 Service Pack

STATUS

Internet Explorer 6

Microsoft has confirmed that this is a problem in Microsoft Internet Explorer 6.

Internet Explorer 5.5

Microsoft has confirmed that this is a problem in Microsoft Internet Explorer 5.5. This problem was first corrected in Internet Explorer version 5.5 Service Pack 2.

Internet Explorer 5.01

Microsoft has confirmed that this is a problem in Microsoft Internet Explorer 5.01. This problem was first corrected in Internet Explorer 5.01 for Windows 2000 Service Pack 3.

MORE INFORMATION

For more information about this vulnerability, visit the following Microsoft Web site:

Modification Type:MinorLast Reviewed:6/7/2005
Keywords:kbbug kbenv kbfix kbgraphxlinkcritical kbIE501preSP3Fix kbIE550PreSP3fix kbIE600preSP1fix kbpatch KbSECBulletin KbSECHack kbSecurity KbSECVulnerability kbWin2000sp3fix kbIE600sp1fix KB286043