Asp.net-mvc – Allow HTML in text boxes

In MVC, validation takes place at the controller level, not at the page level. To see why this is, consider that at the time the controller action is executing, we don't know what view will be chosen to render. (In fact, the controller action might not even render a view at all! It might open a file download prompt on the client instead.) Additionally, if a user is submitting malicious input to the server, by the time the view is rendered it's too late to do anything about it. The controller already will have committed the dangerous input to the database.

Instead, please decorate the controller or action with the attribute [ValidateInput(false)]. This will cause us to suppress request validation for that controller or action.

Setting ValidateRequest to false is one way to work around this error. What you have to decide is whether or not any of these characters are valid input characters for your form. If they are then you need to turn this off and ensure that you handle all user input correctly.

I can't seem to find a list of the dangerous characters, so if anyone knows one it would be of value to have a link to it.

Some good information can be found here.

As a general rule you should always be html encoding any data you place on your site so turning this off should not cause any harm. However if you are not sure if you are, it is best to leave it on and not allow this data in your form.