Buffer Overflow Attack Vulnerability in Stack

Most of the vulnerability based on buffer overflows aim at forcing the execution of malicious code, mainly in order to give a root shell to the user. The malicious instructions are stored in a buffer, which is overflowed to allow an unexpected use of the process, by changing various memory sections. Buffer overflow attacks exploit a need of bounds checking on the size of input being stored in a buffer array. By writing the data into the memory assigned to array, the attacker can make arbitrary changes to program state stored an adjacent to the array. A buffer overflow is an inconsistent, where a process attempts to store data beyond the boundaries of a fixed length buffer. So that the additional data overwrites next memory the techniques to exploit buffer overflow vulnerability vary per architecture, operating system and memory region locations. The overwritten data may include other buffers, variables and program flow data a technically inclined and malicious user may exploit stack-based buffer overflows to manipulate the program[9,10].