Question

What are security issues in asp.net mvc?! and does MVC solved XSS and the others?!

Answer 1

It helps by allowing you to use some specific pieces, but you still have to use them in appropriate places.

• Use the new default <%: that Html Encodes the output
• Use the anti forgery request token
• Use Any of the provided data access solutions. At the lowest possible level, use .Parameters to pass parameters
• Pay attention to every bit of guidance
• don’t dismiss security advisory published, as the recent one affecting asp.net in general: is-asp-net-mvc-vulnerable-to-the-oracle-padding-attack

You still have to understand & question the security aspects.