When a malformed JSONRequest is sent in the X-OWA-UrlPostData in an Exchange Server 2013 or Exchange Server 2016 environment, Outlook Web Access error reporting may respond with a HTTP error 500 in OwaSerializationException. Additionally when you use a tool such as Fiddler or Burp Suite Scanner, you can obtain a callstack that resembles the following:
Note This issue could be a vulnerability for an authenticated remote attacker to access sensitive information.
{"Body":{"ErrorCode":500,"ExceptionName":"OwaSerializationException","FaultMessage":"Cannot deserialize object of type FindConversationJsonRequest","IsTransient":false,"StackTrace":"Microsoft.Exchange.Clients.Owa2.Server.Core.OwaSerializationException: Cannot deserialize object of type FindConversationJsonRequest ---> System.Runtime.Serialization.SerializationException: Element ':root' contains data from a type that maps to the name 'http:\/\/schemas.contoso.com\/2004\/07\/Exchaasdadnge:FindConversationJsonRequest'.
Note This issue could be a vulnerability for an authenticated remote attacker to access sensitive information.