This makes an interesting read .. Found it up on the Security Vulnerability Research & Defense Blog
OWA has two modes: OWA Light (or OWA Basic for Exchange 2003), and OWA Premium. In short, if OWA Light/Basic is used, you are vulnerable to the XSS vulnerability. You can tell whether OWA Light is used via the “Use Outlook Web Access Light” check box in OWA’s logon screen.
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