Authentication is not required to exploit this vulnerability.
The specific flaw exists within the gwia.exe module responsible for parsing e-mail messages received by the server. When the code encounters a Content-Type header it proceeds to parse out string data from within it. The process does not properly check the length of these values before copying them to a fixed-length buffer. This can be abused by a remote attacker to execute arbitrary code under the context of the SYSTEM user.
