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CERT Coordination Center

Outlook Web Access (OWA) executes scripts contained in email attachment opened via Microsoft Internet Explorer (IE)

Vulnerability Note VU#149424

Original Release Date: 2001-08-29 | Last Revised: 2001-08-30


Microsoft Outlook Web Access (OWA) can run malicious scripts on an Exchange server when Internet Explorer (IE) users open email attachments.


OWA allows users to access their email accounts on a Microsoft Exchange server from another host through a web browser. When IE users access their email through some versions of OWA and choose to open an email attachment that contains malicious script in HTML, IE may execute the script on the client side. If executed, the script would have all privileges of the OWA user, including access to and manipulation of messages and folders on the server.

This vulnerability affects OWA implementations in Microsoft Exchange 5.5 and Exchange 2000. Exploitation of this vulnerability requires the user to open an email attachment. This vulnerability applies to all attachments, regardless of the attachment's file type.


Malicious scripts could access all email messages stored on the server, breaching assumed confidentiality of the messages. Malicious scripts could also delete messages or rearrange messages among folders.


Download the patch available from Microsoft through its advisory at:

Take great care when choosing whether to open any email attachment. Do not open any email attachment if you are not sure that its content is safe. A malicious attachment may appear to come from someone you trust. Verify that the attachment was sent intentionally by the sender before opening it.

Vendor Information


Microsoft Affected

Updated:  July 05, 2001



Vendor Statement

"If an attachment contains HTML code including script, the script will be executed when the attachment is opened, regardless of the attachment type."

Vendor Information

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


The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

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Thanks to Microsoft for reporting this vulnerability.

This document was written by Shawn Van Ittersum.

Other Information

CVE IDs: CVE-2001-0340
Severity Metric: 0.68
Date Public: 2001-06-06
Date First Published: 2001-08-29
Date Last Updated: 2001-08-30 15:03 UTC
Document Revision: 17

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