static MagickBooleanType WriteGROUP4Image(const ImageInfo *image_info,
  Image *image)
{
  char
    filename[MaxTextExtent];

  FILE
    *file;

  Image
    *huffman_image;

  ImageInfo
    *write_info;

  int
    unique_file;

  MagickBooleanType
    status;

  register ssize_t
    i;

  ssize_t
    count;

  TIFF
    *tiff;

  toff_t
    *byte_count,
    strip_size;

  unsigned char
    *buffer;

  /*
    Write image as CCITT Group4 TIFF image to a temporary file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == MagickFalse)
    return(status);
  huffman_image=CloneImage(image,0,0,MagickTrue,&image->exception);
  if (huffman_image == (Image *) NULL)
    {
      (void) CloseBlob(image);
      return(MagickFalse);
    }
  huffman_image->endian=MSBEndian;
  file=(FILE *) NULL;
  unique_file=AcquireUniqueFileResource(filename);
  if (unique_file != -1)
    file=fdopen(unique_file,"wb");
  if ((unique_file == -1) || (file == (FILE *) NULL))
    {
      ThrowFileException(&image->exception,FileOpenError,
        "UnableToCreateTemporaryFile",filename);
      return(MagickFalse);
    }
  (void) FormatLocaleString(huffman_image->filename,MaxTextExtent,"tiff:%s",
    filename);
   (void) SetImageType(huffman_image,BilevelType);
   write_info=CloneImageInfo((ImageInfo *) NULL);
   SetImageInfoFile(write_info,file);
  (void) SetImageType(image,BilevelType);
   (void) SetImageDepth(image,1);
   write_info->compression=Group4Compression;
   write_info->type=BilevelType;
   (void) SetImageOption(write_info,"quantum:polarity","min-is-white");
  status=WriteTIFFImage(write_info,huffman_image);
  (void) fflush(file);
  write_info=DestroyImageInfo(write_info);
  if (status == MagickFalse)
    {
      InheritException(&image->exception,&huffman_image->exception);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  tiff=TIFFOpen(filename,"rb");
  if (tiff == (TIFF *) NULL)
    {
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowFileException(&image->exception,FileOpenError,"UnableToOpenFile",
        image_info->filename);
      return(MagickFalse);
    }
  /*
    Allocate raw strip buffer.
  */
  if (TIFFGetField(tiff,TIFFTAG_STRIPBYTECOUNTS,&byte_count) != 1)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  strip_size=byte_count[0];
  for (i=1; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
    if (byte_count[i] > strip_size)
      strip_size=byte_count[i];
  buffer=(unsigned char *) AcquireQuantumMemory((size_t) strip_size,
    sizeof(*buffer));
  if (buffer == (unsigned char *) NULL)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
        image_info->filename);
    }
  /*
    Compress runlength encoded to 2D Huffman pixels.
  */
  for (i=0; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
  {
    count=(ssize_t) TIFFReadRawStrip(tiff,(uint32) i,buffer,strip_size);
    if (WriteBlob(image,(size_t) count,buffer) != count)
      status=MagickFalse;
  }
  buffer=(unsigned char *) RelinquishMagickMemory(buffer);
  TIFFClose(tiff);
  huffman_image=DestroyImage(huffman_image);
  (void) fclose(file);
  (void) RelinquishUniqueFileResource(filename);
  (void) CloseBlob(image);
  return(status);
}

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.