Buffer overflow: teoria e exploração

Abstract

This work is a study about buffer overflow, presenting the architectures of the software and hardware involved. It explains the architectures of the Intel 64 and IA-32 processors, as well as the Linux operating system. These environments were used for the development and exploration of buffer overflow. The problem is detailed and some studies cases shown, exemplifying your exploitation. Basically, buffer overflow occurs during writing in memory regions or arrays. There is interest in show how negligence with computing security during software development can be dangerous for computing environments. The study comments about some of the existing tools to prevent buffer overflow on the Linux operating system. These tools are applied to different contexts and have some level of security; the tools examined are: Libsafe, StackGuard, StackShield, ProPolice and PaX. The larger problem of buffer overflow is mistakes made during development phase. In experiments, it was possible to invade a 32 bits system through attacks in the following overwriting modes: return address and base pointer frame of calling function, and function pointer. On the other hand, it was not possible to exploit the fault in a 64 bits system.