Microsoft has issued patches for Exchange to fix a buffer overflow vulnerability in the SMTP service.

The vulnerability may be exploited by sending a maliciously crafted parameter to an extended verb request.

Exchange 5.5 is only vulnerable to a Denial of Service.

Exchange 2000 is also vulnerable to execution of arbitrary code.

Exchange 2003 is not affected.

Solution
A SMTP gateway or application level firewall may prevent exploitation of these vulnerabilities.
Further details available in Customer Area

Provided and/or discovered by
João Gouveia

Changelog
Further details available in Customer Area

Original Advisory
Vulnerability in Exchange Server Could Allow Arbitrary Code Execution:
http://www.microsoft.com/technet/security/bulletin/MS03-046.asp

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area