Microsoft KB Archive/942638

= POST requests that do not have a POST body may be sent to a Web server that is published in ISA Server 2006 =

Article ID: 942638

Article Last Modified on 10/19/2007

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APPLIES TO


 * Microsoft Internet Security and Acceleration Server 2006 Enterprise Edition
 * Microsoft Internet Security and Acceleration Server 2006 Standard Edition

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SYMPTOMS
Consider the following scenario:
 * You publish a Web server in Microsoft Internet Security and Acceleration (ISA) Server 2006.
 * The ISA Server Web listener is configured to use Windows Integrated NTLM authentication.
 * A user uses Windows Internet Explorer to access the Web server.

In this scenario, POST requests that do not have a POST body may be sent to the published Web server. This problem may cause unexpected Web-access behavior.



CAUSE
When Internet Explorer sends a POST request to a Web site that uses NTLM authentication, Internet Explorer reauthenticates with the Web server for each POST request. The POST body is not sent to the Web server in the first authentication handshake.

If Internet Explorer sends a POST request that requires reauthentication on a TCP connection that has already been authenticated, ISA Server continues to use the current authentication context instead of reauthenticating the client. In this situation, the POST request that does not have a POST body is sent to the published Web server.



RESOLUTION
To resolve this problem, follow these steps:  Apply the hotfix package that is described in the following Microsoft Knowledge Base article:

942639 Description of the ISA Server 2006 hotfix package: September 24, 2007

 Start Notepad.  Copy the following code, and then paste it into Notepad.

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure. However, they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. Const SE_VPS_GUID = &quot;{143F5698-103B-12D4-FF34-1F34767DEabc}&quot; Const SE_VPS_NAME = &quot;EnablePOSTReauthentication&quot; Const SE_VPS_VALUE = true

Sub SetValue

' Create the root object. Dim root ' The FPCLib.FPC root object Set root = CreateObject(&quot;FPC.Root&quot;)

'Declare the other objects needed. Dim array      ' An FPCArray object Dim VendorSets ' An FPCVendorParametersSets collection Dim VendorSet  ' An FPCVendorParametersSet object

' Get references to the array object ' and to the network rules collection. Set array = root.GetContainingArray Set VendorSets = array.VendorParametersSets

On Error Resume Next Set VendorSet = VendorSets.Item( SE_VPS_GUID )

If Err.Number <> 0 Then Err.Clear

' Add the item. Set VendorSet = VendorSets.Add( SE_VPS_GUID ) CheckError WScript.Echo &quot;New VendorSet added... &quot; & VendorSet.Name

Else WScript.Echo &quot;Existing VendorSet found... value- &quot; & VendorSet.Value(SE_VPS_NAME) End If

if VendorSet.Value(SE_VPS_NAME) <> SE_VPS_VALUE Then

Err.Clear VendorSet.Value(SE_VPS_NAME) = SE_VPS_VALUE

If Err.Number <> 0 Then CheckError Else VendorSets.Save false, true CheckError

If Err.Number = 0 Then WScript.Echo &quot;Done with &quot; & SE_VPS_NAME & &quot;, saved!&quot; End If       End If    Else WScript.Echo &quot;Done with &quot; & SE_VPS_NAME & &quot;, no change!&quot; End If

End Sub

Sub CheckError

If Err.Number <> 0 Then WScript.Echo &quot;An error occurred: 0x&quot; & Hex(Err.Number) & &quot; &quot; & Err.Description Err.Clear End If

End Sub

SetValue  Save the file as a Microsoft Visual Basic script file by using the .vbs file name extension. For example, use the following name to save the file:

EnablePOSTReauthentication.vbs

 Start a command prompt, change to the location at which you saved the EnablePOSTReauthentication.vbs file, and then run the following command:

cscript EnablePOSTReauthentication.vbs



Note To revert to the default setting, edit the script by changing &quot;Const SE_VPS_VALUE = true&quot; to &quot;Const SE_VPS_VALUE = false.&quot; Save the script, and then run it again.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

Additional query words: blank POST request without body

Keywords: kbqfe kbexpertiseinter KB942638

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