static int jpeg_nextmarker(Image *ifile, Image *ofile)
{
  int c;

  /* transfer anything until we hit 0xff */
  do
  {
    c = ReadBlobByte(ifile);
    if (c == EOF)
      return M_EOI; /* we hit EOF */
    else
      if (c != 0xff)
        (void) WriteBlobByte(ofile,(unsigned char) c);
  } while (c != 0xff);

  /* get marker byte, swallowing possible padding */
  do
  {
    c = ReadBlobByte(ifile);
    if (c == EOF)
      return M_EOI; /* we hit EOF */
  } while (c == 0xff);

  return c;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.