基于Linux地址空间随机化的缓冲区溢出研究

Buffer Overflow Research based on Address Space Randomization in Linux

缓冲区溢出攻击是一种被广泛利用并危害严重的攻击方式，已经成为计算机系统安全亟待解决的重要问题。在分析缓冲区溢出攻击原理的基础上，给出了主要的防御方法，重点探讨了Linux系统下地址空间随机化防御方法的实现，研究了如何绕过其防护的缓冲区溢出攻击方法，并对其防护效果进行了分析。结果表明，地址空间随机化技术能有效降低缓冲区溢出攻击成功的概率，但不能完全阻止攻击。

Buffer overflow attack has been widely used and could cause great damage. It has become an important issue of computer system security. This paper analyzes the principle of buffer overflow attack, and presents common methods for defending the attack. Then the implementation of defense method for address space randomization in Linux system is mainly discussed, and buffer overflow attack methods for bypassing the defense are proposed. Finally, the effectiveness evaluation of the defense is also given. The results show that address space randomization technique can effectively reduce the probability of successful buffer overflow attacks, but it can not prevent attacks completely.