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Microsoft Windows XMLHTTP component allows remote access to local data sources

Vulnerability Note VU#328163

Original Release Date: 2002-10-01 | Last Revised: 2002-10-02

Overview

The Microsoft XMLHTTP ActiveX control allows unauthorized reading of any known file on a system. A victim must be enticed to visit a malicious site in order to be attacked.

Description

Description (from MS02-008):

Microsoft XML Core Services (MSXML) includes the XMLHTTP ActiveX
control, which allows web pages rendering in the browser to send or
receive XML data via HTTP operations such as POST, GET, and PUT.
The control provides security measures designed to restrict web
pages so they can only use the control to request data from remote
data sources.

A flaw exists in how the XMLHTTP control applies IE security zone
settings to a redirected data stream returned in response to a
request for data from a web site. A vulnerability results because
an attacker could seek to exploit this flaw and specify a data
source that is on the user's local system. The attacker could
then use this to return information from the local system to the
attacker's web site.

Preconditions (from MS02-008):

 - The vulnerability can only be exploited via a web site.
  It would not be possible to exploit this vulnerability
  via HTML mail.

 - The attacker would need to know the full path and file name
  of a file in order to read it.

Impact

A remote attacker who can entice a victim to visit a malicious web site can read any file the user can. Note this vulnerability is not believed to allow file modification (no file writing, inserting, or deleting).

Solution

Apply the patches found in MS02-008.


http://www.microsoft.com/windows/ie/downloads/critical/q317244/download.asp

Microsoft has confirmed that this problem could result in some degree of security vulnerability in Microsoft XML 4.0. This problem was corrected in Microsoft XML 4.0 Service Pack 1.

To download MSXML 4.0 Service Pack 1, visit the following Microsoft Web site:

http://msdn.microsoft.com/downloads/default.asp?url=/downloads/sample.asp?url=/msdn-files/027/001/766/msdncompositedoc.xml

MSXML can also be installed separately. MSXML is installed as a DLL in the System32 subfolder of the Windows operating system folder. On most systems, this will likely be C:\Windows or C:\winnt. If you have any or all of the following files in the System32 folder, you need the patch:

    • Msxml2.dll
    • Msxml3.dll
    • Msxml4.dll

If you have only Msxml.dll, you do not need the patch because this is an earlier, unaffected version.

Vendor Information

328163
 

Microsoft Corporation Affected

Updated:  October 02, 2002

Status

Affected

Vendor Statement

Please see MS02-008:

http://www.microsoft.com/technet/security/bulletin/ms02-008.asp

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

-----BEGIN PGP SIGNED MESSAGE-----

- ----------------------------------------------------------------------
Title:      XMLHTTP Control Can Allow Access to Local Files
Date:       21 February 2002
Software:   Microsoft XML Core Services
Impact:     Information disclosure
Max Risk:   Critical
Bulletin:   MS02-008

Microsoft encourages customers to review the Security Bulletin at:
http://www.microsoft.com/technet/security/bulletin/MS02-008.asp.
- ----------------------------------------------------------------------

Issue:
======
Microsoft XML Core Services (MSXML) includes the XMLHTTP ActiveX
control, which allows web pages rendering in the browser to send or
receive XML data via HTTP operations such as POST, GET, and PUT.
The control provides security measures designed to restrict web
pages so they can only use the control to request data from remote
data sources.

A flaw exists in how the XMLHTTP control applies IE security zone
settings to a redirected data stream returned in response to a
request for data from a web site. A vulnerability results because
an attacker could seek to exploit this flaw and specify a data
source that is on the user's local system. The attacker could
then use this to return information from the local system to the
attacker's web site.

An attacker would have to entice the user to a site under his
control to exploit this vulnerability. It cannot be exploited
by HTML email. In addition, the attacker would have to know the
full path and file name of any file he would attempt to read.
Finally, this vulnerability does not give an attacker any
ability to add, change or delete data.

Mitigating Factors:
====================
- The vulnerability can only be exploited via a web site.
  It would not be possible to exploit this vulnerability
  via HTML mail.

 - The attacker would need to know the full path and file name
  of a file in order to read it.

 - The vulnerability does not provide any ability to add,
  change, or delete files.

Risk Rating:
============
- Internet systems: Moderate
- Intranet systems: Moderate
- Client systems: Critical

Patch Availability:
===================
- A patch is available to fix this vulnerability. Please read the
  Security Bulletin at
 
http://www.microsoft.com/technet/security/bulletin/ms02-008.asp
  for information on obtaining this patch.

- ---------------------------------------------------------------------

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS
ALL
WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
IN NO EVENT
SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY
DAMAGES
WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL,
LOSS OF
BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR
ITS
SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME
STATES DO
NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL
OR
INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

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*******************************************************************

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References

Acknowledgements

This document was written by Jeffrey S. Havrilla based on information provided by Microsoft.

Other Information

CVE IDs: CVE-2002-0057
Severity Metric: 10.40
Date Public: 2001-12-17
Date First Published: 2002-10-01
Date Last Updated: 2002-10-02 15:38 UTC
Document Revision: 28

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