Authentication might be required to exploit this vulnerability. The specific flaw exists within imailsrv.exe which is invoked to handle messages sent to the imailsrv. When a message subject contains a "?Q?" operator the string following that sequence is copied to a local stack buffer. No validation of the data or data length is done. In order to reach this code path a mailing list must be password protected (authentication required) or have previously had a password configured (no authentication required). A remote attacker can exploit this vulnerability to execute arbitrary code under the context of the SYSTEM user.
Disclosure Timeline:
2010-06-08 - Vulnerability reported to vendor
2010-07-15 - Coordinated public release of advisory
