Microsoft KB Archive/823646

= ISA Server Forces CERN FTP Connections to the Root Directory =

Article ID: 823646

Article Last Modified on 6/14/2007

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APPLIES TO


 * Microsoft Internet Security and Acceleration Server 2000 Standard Edition
 * Microsoft Internet Security and Acceleration Server 2000 Service Pack 1

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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
By using a Web browser to connect to an FTP site, a user may unexpectedly be connected to the root directory of the FTP server. Or, the user may not be able to access a directory if a URL path is specified.



CAUSE
This issue may occur if the Web browser is configured to use Microsoft Internet Security and Acceleration (ISA) Server 2000 as a Web proxy for FTP requests -- specifically, when the FTP server requires the user to authenticate, and the server is configured to put the user in a directory that is relative to the root of the FTP server. For authenticated users, the FTP implementation in Microsoft Internet Information Server (IIS) 4.0 and in Microsoft Internet Information Services (IIS) 5.0 tries to change the remote directory to either a directory or a virtual directory that matches the user's name. If such a directory exists, the user is put in this directory, and this directory is relative to the FTP server's root directory. Administrators may use this method to put users in their respective home directories and in this way partly sandbox users.

However, users are not restricted from changing to the root directory of the FTP server in this scenario. A user who uses a Web browser to connect to an FTP server that uses IIS 4.0 and IIS 5.0 functionality may instead end up in the FTP root directory and, for example, see a list of other users' home directories. If virtual directories are used, the user's home directory may not appear in the list unless a matching directory exists in the FTP root.

Note The FTP implementation in IIS 6.0 supports a new feature that is named User Isolation. This feature permits the administrator to fully sandbox users. Users who connect to an FTP server that is running IIS 6.0 (or to a server that supports similar user isolation) will not be affected by the issue that is described in the &quot;Symptoms&quot; section. The reason for this is that IIS 6.0 users are put in their own respective root directories and not in any directory that is relative to the root of their respective FTP servers.

ISA Server issues a CWD /  command immediately after a successful logon, where the  portion of the command is the   portion of the URL. The problem that is described in the &quot;Symptoms&quot; section occurs because ISA Server does not drop the leading slash mark (/) from the path. RFC 1738 Section 3.1 specifies that the slash mark that appears between the host (or the port) and the URL path is not part of the URL path. ISA Server is not compliant with RFC 1738, because it uses the leading slash mark (/) as part of the path. Therefore, ISA Server issues the initial CWD command as “/ / ” instead of as “ / ” as specified in RFC 1738.

Note Most authenticated FTP servers can be expected to use a directory that is relative to a particular user's user name for an authenticated user's FTPRoot directory.



WORKAROUND
Users may be able to work around this issue by including the relative directory path in the request. For example, a user who wants to connect to an FTP server and be put in the &quot;sub-dir&quot; directory (sub-dir is relative to the user's home directory) must use the following request:

ftp:// : /sub-dir/

If the relative path is different from the user name, the user can use a command-line FTP client such as FTP.EXE to connect to the FTP server and issue a PWD command. The PWD command will return the current directory relative to the FTP server's root.



RESOLUTION
For more information about how to obtain the latest ISA Server 2000 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

313139 How to Obtain the Latest Internet Security and Acceleration Server 2000 Service Pack

A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

The English version of this hotfix 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. Note You must install ISA Server Service Pack 1 (SP1) before you install the following hotfix. This hotfix also applies to the French, the German, the Spanish, and the Japanese versions of ISA Server.   Date         Time   Version            Size    File name ---  20-Jul-2003  20:57  3.0.1200.283      178,448  Mspadmin.exe 20-Jul-2003 20:57  3.0.1200.283      103,184  Msphlpr.dll 20-Jul-2003 20:56  3.0.1200.283      392,464  W3proxy.exe 20-Jul-2003 20:57  3.0.1200.283      299,280  Wspsrv.exe



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



MORE INFORMATION
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. To install the hotfix, run the self-extracting file. You do not have to restart the ISA Server computer. If the computer is part of an ISA Server array, you do not have to shut down the whole array. You can still install this hotfix on a one-by-one basis.

To implement the functionality in this hotfix, create the following registry key:

 Stop the Web Proxy service. Start Registry Editor. Locate and select the following registry key:

 Create a new DWORD value that is named. Give this new value a data value of 1.</li> Restart the Web Proxy service.</li></ol>

To revert to the original configuration, either remove the  registry value or change its data value to 0 (zero). After you make either change, restart the Web Proxy service.

Keywords: kbhotfixserver kbqfe kbisaserv2000presp2fix kbfix kbbug KB823646

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