buffer overflow

Writing past the end of an array or buffer, so the extra bytes land on whatever is stored next to it in memory. Not the same thing as integer overflow.

A buffer overflow is an out-of-bounds write beyond a buffer's end (or before its start); on the stack it overwrites neighbouring locals, saved registers, the saved frame pointer and the saved return address in the frame, and on the heap it overwrites adjacent blocks and allocator metadata.

Examples

char buf[8]; strcpy(buf, "overflowing"); writes 12 bytes into an 8-byte array.