Outlook Web App (OWA) in Microsoft Exchange Server 2013 SP1 and Cumulative Update 6 does not properly validate redirection tokens, which allows remote attackers to redirect users to arbitrary web sites and spoof the origin of e-mail messages via unspecified vectors, aka "Exchange URL Redirection Vulnerability."
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.