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Microsoft Windows SMTP component vulnerable to remote code execution

Vulnerability Note VU#394792

Original Release Date: 2004-10-13 | Last Revised: 2004-11-29


A vulnerability in the mail handling service in some versions of Microsoft Windows could allow a remote attacker to compromise the affected system.


The Simple Mail Transfer Protocol (SMTP) is the most common protocol for the delivery of electronic mail between systems on the Internet. Some versions of Microsoft Windows support the ability to act as an SMTP server. The ability to interact with the Domain Name System (DNS) is critical for an SMTP server to deliver mail to a remote user (e.g., A buffer management flaw exists in the way that the SMTP service handles DNS responses. A remote attacker with the ability to craft DNS response messages could exploit this vulnerability to compromise the affected system.


A remote, unauthenticated attacker may be able to execute arbitrary code with administrative privileges on an affected system.


Apply a patch from the vendor

Microsoft has published Microsoft Security Bulletin MS04-035 in response to this issue. Users are strongly encouraged to review this bulletin and apply the patches it refers to.


In addition to the patches referenced above, Microsoft has published workarounds for this issue. Users who are unable to apply the patches are strongly encouraged to implement these workarounds as appropriate.

Vendor Information


Microsoft Corporation Affected

Updated:  October 13, 2004



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

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


Microsoft has published patches to address this vulnerability. Please see Microsoft Security Bulletin MS04-035 for more information.

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

CVSS Metrics

Group Score Vector



Thanks to Microsoft Security for reporting this vulnerability.

This document was written by Chad R Dougherty based on information provided by Microsoft.

Other Information

CVE IDs: CVE-2004-0840
Severity Metric: 23.94
Date Public: 2004-10-12
Date First Published: 2004-10-13
Date Last Updated: 2004-11-29 20:34 UTC
Document Revision: 11

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