An attacker changes the address of a sub-routine in such a manner that it begins...

An attacker changes the address of a sub-routine in such a manner that it begins to point to the address of the malicious code. As a result, when the function has been exited, the application can be forced to shift to the malicious code. The image given below explains this phenomenon:

Which of the following tools can be used as a countermeasure to such an attack?