Source : Free On-Line Dictionary of Computing

buffer overflow
     
         What happens when you try to store more data in
        a {buffer} than it can handle.  This may be due to a mismatch
        in the processing rates of the producing and consuming
        processes (see {overrun} and {firehose syndrome}), or because
        the buffer is simply too small to hold all the data that must
        accumulate before a piece of it can be processed.  For
        example, in a text-processing tool that {crunch}es a line at a
        time, a short line buffer can result in {lossage} as input
        from a long line overflows the buffer and overwrites data
        beyond it.  Good defensive programming would check for
        overflow on each character and stop accepting data when the
        buffer is full.
     
        See also {spam}, {overrun screw}.
     
        [{Jargon File}]
     
        (1996-05-13)