Auto-ASX File Generation Potentially Reveals Internal Server Name of Server (279467)


The information in this article applies to:

  • Microsoft Windows Media Services 4.1
This article was previously published under Q279467
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

When you automatically generate the Advanced Stream Redirector (.asx) file, you potentially reveal the internal name of the server.

CAUSE

Windows Media Server incorrectly populates the ASX response with an entry that may be composed of sensitive information in certain configurations.

RESOLUTION

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 are experiencing this specific problem.

To resolve this problem immediately, download the fix by clicking the download link 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:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

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 English version of this fix should have the following file attributes or later: 
  Date        Time   Version      Size     File name  OS
  ------------------------------------------------------------------
  11/10/2000  19:45  4.1.0.3858   440,816  NSUM.EXE   Windows NT 4.0
  11/10/2000  19:46  4.1.0.3920   441,328  NSUM.EXE   Windows 2000

This fix is also available for download from the Microsoft Download Center. Click the file name below to download the file:

Wmsu28778.exe

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.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

Windows Media Server generates and returns ASX-type references when a non-Windows Media Player program (such as a browser) requests a streaming file. In this case, Windows Media Server can incorrectly populate the ASX response with an entry that may be composed of sensitive information in certain configurations. For example, see the following response: 

[Reference]

Ref1=http://internal:80/file.asf
Ref2=http://x.x.x.x:80/file.asf

The server that is used to obtain this response does not have the server name, "internal", externally registered on the Internet; it is the local computer name. Instead, the Domain Name System (DNS) name, "netshowserver.com", should have been returned.

Another solution is to completely remove the first reference and return only the server IP address reference that matches the control connection. To control the reference that is returned, perform the following steps:

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
  1. Start Registry Editor (Regedt32.exe).
  2. Locate the following key in the registry:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\nsunicast\Parameters

  3. On the Edit menu, click Add Value, and then add the following registry value:

    Value Name: SendDomainNameURLInRedirectASX
    Data Type: REG_DWORD
    Value: 0 or 1. Default is off.

    When the SendDomainNameURLInRedirectASX value is set to off (0), the ASX reference only has an Internet Protocol (IP) address. When SendDomainNameURLInRedirectASX is set to 1, the ASX reference has both a DNS server name and an IP address.
  4. Quit Registry Editor.
Modification Type:MinorLast Reviewed:9/23/2005
Keywords:kbHotfixServer kbQFE kbdownload kbdownload kbfile kbprb kbQFE KB279467
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