What is a buffer overflow?
A buffer overflow is when a buffer was assigned by a programmer to hold variable data, and the variable data placed into that buffer is greater that the size of the initial assignment of the buffer. Depending on the operating system and exactly what the “extra” data overflowing the buffer is, this can be used by a hacker to cause portions of a system to fail, or even execute arbitrary code. Most buffer overflow exploits center around user-supplied data exceeding a buffer, and the extra data being executed on the stack to open up additional access. Buffer overflows exist on all major network operating systems. For a more deteailed explanation, read Smashing The Stack For Fun And Profit by Aleph1.
