Source : Free On-Line Dictionary of Computing

overrun screw
     
        A variety of {fandango on core} produced by a {C} program
        scribbling past the end of an {array} ({C} implementations
        typically have no checks for this error).  This is relatively
        benign and easy to spot if the array is static; if it is
        {auto}, the result may be to {smash the stack} - often
        resulting in {heisenbug}s of the most diabolical subtlety.
        The term "overrun screw" is used especially of scribbles
        beyond the end of arrays allocated with {malloc}; this
        typically overwrites the allocation header for the next block
        in the {arena}, producing massive lossage within malloc and
        often a {core dump} on the next operation to use {stdio} or
        malloc itself.
     
        See {spam}, {overrun}; see also {memory leak}, {memory smash},
        {aliasing bug}, {precedence lossage}, {fandango on core},
        {secondary damage}.
     
        (1995-01-19)