Microsoft Outlook Web Access vulnerable to cross-site scripting

2005-06-14T00:00:00
ID VU:300373
Type cert
Reporter CERT
Modified 2005-06-14T00:00:00

Description

Overview

Microsoft Outlook Web Access may be vulnerable to cross-site scripting attacks.

Description

Microsoft Outlook Web Access (OWA) allows users to access their email accounts on a Microsoft Exchange server from another host through a web browser.

Microsoft Outlook Web Access for Exchange Server 5.5 contains a flaw in the HTML encoding routines used in the Compose New Message form that may allow an attacker to send a specially-crafted message to a user which then in turn runs a malicious script in the security context of the user reading the mail message.


Impact

A remote unauthenticated attacker may be able to execute arbitrary script code in the security context of the user reading the mail.


Solution

Apply An Update

Please see Microsoft Security Bulletin MS05-029 for more information, such as workarounds and patches.


Utilize Workarounds

Microsoft Security Bulletin MS05-029 recommends a number of workarounds, including:

Uninstall Outlook Web Access

Disable Outlook Web Access for each Exchange site

Modify the Read.asp file to not encode HTML mail with the appropriate HTML markup


Systems Affected

Vendor| Status| Date Notified| Date Updated
---|---|---|---
Microsoft Corporation| | -| 14 Jun 2005
If you are a vendor and your product is affected, let us know.

CVSS Metrics

Group | Score | Vector
---|---|---
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A

References

  • <http://www.microsoft.com/technet/security/bulletin/MS05-029.mspx>
  • <http://www.microsoft.com/exchange/en/55/help/default.asp?url=/exchange/en/55/help/documents/server/xog18001.htm?id=685>

Credit

Thanks to Microsoft for information on this issue, who in turn thank Gaël Delalleau working with iDEFENSE for reporting this vulnerability.

This document was written by Ken MacInnis.

Other Information

  • CVE IDs: CAN-2005-0563
  • Date Public: 14 Jun 2005
  • Date First Published: 14 Jun 2005
  • Date Last Updated: 14 Jun 2005
  • Severity Metric: 11.70
  • Document Revision: 6