Protection of Web applications is an activity that requires constant
monitoring of security threats as well as looking for solutions in this field.
Since protection has moved from the lower layers of OSI models to the
application layer and having in mind the fact that 75% of all the attacks are
performed at the application layer, special attention should be paid to the
application layer. It is possible to improve protection of Web application on
the level of the system architecture by introducing new components which will
realize protection on higher levels of OSI models.