A buffer overflow exploit is an attack technique that exploits a software design defect in an application or process to force it to execute code on the computer. Applications have fixed-size buffers that hold data. If an attacker sends too much data or code into one of these buffers, the buffer overflows. The computer then executes the code that overflowed as a program. Since the code execution occurs in the security content of the application, which is often at a highly-privileged or administrative level, intruders gain access to execute commands not usually accessible to them. An attacker can use this vulnerability to execute custom hacking code on the computer and compromise its security and data integrity.