Microsoft CVE-2018-0941: Microsoft Exchange Information Disclosure Vulnerability

An information disclosure vulnerability exists in the way that Microsoft Exchange Server handles importing data. If an impacted user is using Microsoft Exchange Outlook Web Access (OWA), the vulnerability could allow an attacker to discover sensitive information that should otherwise not be disclosed.
To exploit the vulnerability, an attacker would have to upload a specially crafted file to Microsoft Exchange Outlook Web Access (OWA).
The security update addresses the vulnerability by correcting how Microsoft Exchange handles importing data.