Vulnerability Note VU#300373

Microsoft Outlook Web Access vulnerable to cross-site scripting

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.

II. Impact

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	Vulnerable	14-Jun-2005

References

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

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