Customizing Protocol Inspections
ASDM enables you to add your own customized service policies. Because the ASA/PIX ships with such a strong security posture by default, no customizations are “required” to ensure additional security. This section does, however, cover how to create a customized service policy should you decide that it's important for your deployment.
The example used is the creation of a service policy that checks the length of a URL and drops the packet if the length is too long. This policy could be effective for preventing hackers from both attempting to guess a URL that could cause buffer overflows or passing URLs that contain SQL commands in an attempt to gain access to a back-end SQL database.
This policy is only one example ...