Microsoft Knowledge Base Article - Q326886

MS02-042: Flaw in Network Connection Manager Can Cause Rights Elevation

The information in this article applies to:
  • Microsoft Windows 2000, 2000 SP1, 2000 SP2, 2000 SP3 Professional
  • Microsoft Windows 2000, 2000 SP1, 2000 SP2, 2000 SP3 Server
  • Microsoft Windows 2000, 2000 SP1, 2000 SP2, 2000 SP3 Advanced Server


The Network Connection Manager provides a controlling mechanism for all network connections that are managed by a host computer. Among the functions of the Network Connection Manager is to call a handler routine whenever a network connection has been established.

By design, this handler routine runs in the security context of the user. However, a flaw can make it possible for an unprivileged user to cause the handler routine to run in the security context of LocalSystem. This is possible by using a very complex process. An attacker who exploited this flaw can specify code of his or her choice as the handler. The attacker can then establish a network connection to cause that code to be started by the Network Connection Manager. The code would then run with full system privileges.


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.

Download Information

The following file is available for download from the Microsoft Download Center:
Release Date: August 15, 2002

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
Q119591 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 secure servers that prevent any unauthorized changes to the file.

Installation Information

You must restart your computer after you apply this update. This update supports the following Setup switches:
  • -? Display the list of installation switches.
  • -u Unattended mode.
  • -f Force other programs to quit when the computer shuts down.
  • -n Do not back up files for removal.
  • -o Overwrite OEM files without prompting.
  • -z Do not restart when installation is complete.
  • -q Quiet mode (no user interaction).
  • -l List installed hotfixes.
  • -x Extracts the files without running Setup.
For example, the q326886_w2k_sp4_x86_en -q -z command installs the update without any user intervention and then does not force the computer to restart.

WARNING: Your computer is vulnerable until you restart it.

File Information

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
   Date         Time   Version        Size    File name and path
   24-Jul-2002  21:41  5.0.2195.5974  96,016  %windir%\System32\Netman.dll
NOTE: Because of file dependencies, this update may contain additional files. This update requires Windows 2000 Service Pack 3 (SP3) or Service Pack 2 (SP2). For additional information about how to obtain the latest service pack, click the article number below to view the article in the Microsoft Knowledge Base:
Q260910 How to Obtain the Latest Windows 2000 Service Pack


Microsoft has confirmed that this problem may cause a degree of security vulnerability in the Microsoft products that are listed at the beginning of this article.


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