Content Summary : Applications based upon Ajax are affected by the same problems of any other web application, but usually are more complex because of their asynchronous nature. During development it's important to take care of all singular aspects, without focusing only on some functionalities and on features related to business needs. Superior framework complexity can lead developers to not refine the security aspects and to shorten the testing process. In addition it's a common thought to consider asynchronous requests non duplicable events outside the application. It's important to point out that such requests are based on client-side HTTP protocol which is not reliable from a security point of view (the sender can be impersonated if TLS is not used).Ajax problems are present both client side and server side and can be classified as follows: