Microsoft Exchange 2003 and Outlook Web Access (OWA), when configured to use NTLM authentication, does not properly reuse HTTP connections, which can cause OWA users to view mailboxes of other users when Kerberos has been disabled as an authentication method for IIS 6.0, e.g. when SharePoint Services 2.0 is installed.
Exposure of Sensitive Information to an Unauthorized Actor The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.