Technical Information

Brief overview of the risk:
This security update resolves three publicly disclosed vulnerabilities in Microsoft Exchange Server. The vulnerabilities exist in the WebReady Document Viewing and Data Loss Prevention features of Microsoft Exchange Server. The vulnerabilities could allow remote code execution in the security context of the transcoding service on the Exchange server if a user previews a specially crafted file using Outlook Web App (OWA). The transcoding service in Exchange that is used for WebReady Document Viewing uses the credentials of the LocalService account. The Data Loss Prevention feature hosts code that could allow remote code execution in the security context of the Filtering Management service if a specially crafted message is received by the Exchange server.
Detailed Information on the risk:

The vulnerabilities could allow remote code execution as the LocalService account if a user views a specially crafted file through Outlook Web Access in a browser. An attacker who successfully exploited this vulnerability could run code on the affected Exchange Server, but only as the LocalService account.

Further information on this exploit is available at : MS13-061