static Image *ReadWBMPImage(const ImageInfo *image_info,
  ExceptionInfo *exception)
{
  Image
    *image;

  int
    byte;

  MagickBooleanType
    status;

  register IndexPacket
    *indexes;

  register ssize_t
    x;

  register PixelPacket
    *q;

  ssize_t
    y;

  unsigned char
    bit;

  unsigned short
    header;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  image=AcquireImage(image_info);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  if (ReadBlob(image,2,(unsigned char *) &header) == 0)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  if (header != 0)
    ThrowReaderException(CoderError,"OnlyLevelZerofilesSupported");
  /*
    Initialize image structure.
  */
  if (WBMPReadInteger(image,&image->columns) == MagickFalse)
    ThrowReaderException(CorruptImageError,"CorruptWBMPimage");
  if (WBMPReadInteger(image,&image->rows) == MagickFalse)
    ThrowReaderException(CorruptImageError,"CorruptWBMPimage");
  if ((image->columns == 0) || (image->rows == 0))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  if (DiscardBlobBytes(image,image->offset) == MagickFalse)
    ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
      image->filename);
  if (AcquireImageColormap(image,2) == MagickFalse)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
  if (image_info->ping != MagickFalse)
    {
       (void) CloseBlob(image);
       return(GetFirstImageInList(image));
     }
  status=SetImageExtent(image,image->columns,image->rows);
  if (status == MagickFalse)
    {
      InheritException(exception,&image->exception);
      return(DestroyImageList(image));
    }
   /*
     Convert bi-level image to pixel packets.
   */
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
    if (q == (PixelPacket *) NULL)
      break;
    indexes=GetAuthenticIndexQueue(image);
    bit=0;
    byte=0;
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      if (bit == 0)
        {
          byte=ReadBlobByte(image);
          if (byte == EOF)
            ThrowReaderException(CorruptImageError,"CorruptImage");
        }
      SetPixelIndex(indexes+x,(byte & (0x01 << (7-bit))) ? 1 : 0);
      bit++;
      if (bit == 8)
        bit=0;
    }
    if (SyncAuthenticPixels(image,exception) == MagickFalse)
      break;
    status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
    if (status == MagickFalse)
      break;
  }
  (void) SyncImage(image);
  if (EOFBlob(image) != MagickFalse)
    ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
      image->filename);
  (void) CloseBlob(image);
  return(GetFirstImageInList(image));
}

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.