Buffer Overflow

Buffer Overflow 会引起一些安全问题，一些attacker会利用这些漏洞对系统进行攻击。


主要方式是将Return address修改；
现在有三种方法来尽量避免因为Buffer Overflow而导致的安全问题；

1. Stack Randomization;
    The idea of stack randomizatin is to make the position of stack vary from one run of a program to another;
    
2. Stack Corruption Detection;
    A second line of defence is to be able to detect when a stack  has been corrupted;


3. Limiting Executable Code Regions;
    A final step is to eliminate  the ability  of attacker to insert executable code  into a systeml.  One method is  to limit which memory regions  hold executable code.


The techniques we  have outlined    are three of the most common mechanisms used to minimize  the vulnerability programs to buffer overflow attacks.