DOCUMENT:Q320374  15-AUG-2002  [iis]
TITLE   :MS02-018: Patch Available for Cross-site Scripting Vulnerability
PRODUCT :Internet Information Server
PROD/VER::5.0
OPER/SYS:
KEYWORDS:kbenv kbSecurity kbWin2000PreSP3Fix kbWinXPpreSP1fix kbWin2000sp3fix

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The information in this article applies to:

 - Microsoft Internet Information Services version 5.1 
 - Microsoft Internet Information Services version 5.0 
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SYMPTOMS
========

A cross-site scripting (CSS) vulnerability exists in Internet Information
Services (IIS) 5.0 and 5.1. Through this vulnerability, it could be possible for
an attacker to send a request to an affected server that would cause a Web page
that contains script to be sent to another user. The script would execute within
the user's browser as though it had come from the third-party site. This would
let it run by using the security settings that are appropriate to the
third-party Web site, and provide the attacker with access to any data that the
site owns.

This vulnerability could only be exploited if the user opened an HTML mail
message or visited a malicious user's Web site. The code cannot be "injected"
into an existing session.

CAUSE
=====

This vulnerability occurs because a customized message service in IIS does not
properly validate all inputs before they are used. The customized message is
what is returned when someone requests a Web page that does not exist on the
server.

Note that the default error message in IIS is unaffected by this vulnerability.

RESOLUTION
==========

 - Internet Information Services 5.1
 - Internet Information Services 5.0

Internet Information Services 5.1
---------------------------------

The update for this problem is included in the "MS02-018: April 2002 Cumulative
Patch for Internet Information Services". For additional information about how
to obtain this patch, click the article number below to view the article in the
Microsoft Knowledge Base:

   Q319733 MS02-018: April 2002 Cumulative Patch for Internet Information
   Services

Internet Information Services 5.0
---------------------------------

The update for this problem is included in the "MS02-018: April 2002 Cumulative
Patch for Internet Information Services". For additional information about how
to obtain this patch, click the article number below to view the article in the
Microsoft Knowledge Base:

   Q319733 MS02-018: April 2002 Cumulative Patch for Internet Information
   Services

STATUS
======

Internet Information Services 5.1
---------------------------------

Microsoft has confirmed that this problem may cause a degree of security
vulnerability in Microsoft Internet Information Services 5.1.

Internet Information Services 5.0
---------------------------------

Microsoft has confirmed that this problem may cause a degree of security
vulnerability in Microsoft Internet Information Services 5.0.

MORE INFORMATION
================

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

   http://www.microsoft.com/technet/security/bulletin/MS02-018.asp

Additional query words: security_patch kbIIS400500510April2002Rollup

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Keywords          : kbenv kbSecurity kbWin2000PreSP3Fix kbWinXPpreSP1fix kbWin2000sp3fix 
Technology        : kbiisSearch kbiis500 kbiis510
Version           : :5.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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