static Image *ReadPDBImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  unsigned char
    attributes,
    tag[3];

  Image
    *image;

  IndexPacket
    index;

  MagickBooleanType
    status;

  PDBImage
    pdb_image;

  PDBInfo
    pdb_info;

  register IndexPacket
    *indexes;

  register ssize_t
    x;

  register PixelPacket
    *q;

  register unsigned char
    *p;

  size_t
    bits_per_pixel,
    num_pad_bytes,
    one,
    packets;

  ssize_t
    count,
    img_offset,
    comment_offset = 0,
    y;

  unsigned char
    *pixels;

  /*
    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);
    }
  /*
    Determine if this a PDB image file.
  */
  count=ReadBlob(image,32,(unsigned char *) pdb_info.name);
  pdb_info.attributes=(short) ReadBlobMSBShort(image);
  pdb_info.version=(short) ReadBlobMSBShort(image);
  pdb_info.create_time=ReadBlobMSBLong(image);
  pdb_info.modify_time=ReadBlobMSBLong(image);
  pdb_info.archive_time=ReadBlobMSBLong(image);
  pdb_info.modify_number=ReadBlobMSBLong(image);
  pdb_info.application_info=ReadBlobMSBLong(image);
  pdb_info.sort_info=ReadBlobMSBLong(image);
  count=ReadBlob(image,4,(unsigned char *) pdb_info.type);
  count=ReadBlob(image,4,(unsigned char *) pdb_info.id);
  if ((count == 0) || (memcmp(pdb_info.type,"vIMG",4) != 0) ||
      (memcmp(pdb_info.id,"View",4) != 0))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  pdb_info.seed=ReadBlobMSBLong(image);
  pdb_info.next_record=ReadBlobMSBLong(image);
  pdb_info.number_records=(short) ReadBlobMSBShort(image);
  if (pdb_info.next_record != 0)
    ThrowReaderException(CoderError,"MultipleRecordListNotSupported");
  /*
    Read record header.
  */
  img_offset=(ssize_t) ((int) ReadBlobMSBLong(image));
  attributes=(unsigned char) ((int) ReadBlobByte(image));
  (void) attributes;
  count=ReadBlob(image,3,(unsigned char *) tag);
  if (count != 3  ||  memcmp(tag,"\x6f\x80\x00",3) != 0)
    ThrowReaderException(CorruptImageError,"CorruptImage");
  if (pdb_info.number_records > 1)
    {
      comment_offset=(ssize_t) ((int) ReadBlobMSBLong(image));
      attributes=(unsigned char) ((int) ReadBlobByte(image));
      count=ReadBlob(image,3,(unsigned char *) tag);
      if (count != 3  ||  memcmp(tag,"\x6f\x80\x01",3) != 0)
        ThrowReaderException(CorruptImageError,"CorruptImage");
    }
  num_pad_bytes = (size_t) (img_offset - TellBlob( image ));
  while (num_pad_bytes--) ReadBlobByte( image );
  /*
    Read image header.
  */
  count=ReadBlob(image,32,(unsigned char *) pdb_image.name);
  pdb_image.version=ReadBlobByte(image);
  pdb_image.type=(unsigned char) ReadBlobByte(image);
  pdb_image.reserved_1=ReadBlobMSBLong(image);
  pdb_image.note=ReadBlobMSBLong(image);
  pdb_image.x_last=(short) ReadBlobMSBShort(image);
  pdb_image.y_last=(short) ReadBlobMSBShort(image);
  pdb_image.reserved_2=ReadBlobMSBLong(image);
  pdb_image.x_anchor=ReadBlobMSBShort(image);
  pdb_image.y_anchor=ReadBlobMSBShort(image);
  pdb_image.width=(short) ReadBlobMSBShort(image);
  pdb_image.height=(short) ReadBlobMSBShort(image);
  /*
    Initialize image structure.
  */
  image->columns=(size_t) pdb_image.width;
  image->rows=(size_t) pdb_image.height;
  image->depth=8;
  image->storage_class=PseudoClass;
  bits_per_pixel=pdb_image.type == 0 ? 2UL : pdb_image.type == 2 ? 4UL : 1UL;
  one=1;
  if (AcquireImageColormap(image,one << bits_per_pixel) == 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));
    }
   packets=(bits_per_pixel*image->columns+7)/8;
   pixels=(unsigned char *) AcquireQuantumMemory(packets+256UL,image->rows*
     sizeof(*pixels));
  if (pixels == (unsigned char *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
  switch (pdb_image.version & 0x07)
  {
    case 0:
    {
      image->compression=NoCompression;
      count=(ssize_t) ReadBlob(image, packets * image -> rows, pixels);
      break;
    }
    case 1:
    {
      image->compression=RLECompression;
      if (!DecodeImage(image, pixels, packets * image -> rows))
        ThrowReaderException( CorruptImageError, "RLEDecoderError" );
      break;
    }
    default:
      ThrowReaderException(CorruptImageError,
         "UnrecognizedImageCompressionType" );
  }
  p=pixels;
  switch (bits_per_pixel)
  {
    case 1:
    {
      int
        bit;

      /*
        Read 1-bit PDB image.
      */
      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);
        for (x=0; x < ((ssize_t) image->columns-7); x+=8)
        {
          for (bit=0; bit < 8; bit++)
          {
            index=(IndexPacket) (*p & (0x80 >> bit) ? 0x00 : 0x01);
            SetPixelIndex(indexes+x+bit,index);
          }
          p++;
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      (void) SyncImage(image);
      break;
    }
    case 2:
    {
      /*
        Read 2-bit PDB image.
      */
      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);
        for (x=0; x < (ssize_t) image->columns; x+=4)
        {
          index=ConstrainColormapIndex(image,3UL-((*p >> 6) & 0x03));
          SetPixelIndex(indexes+x,index);
          index=ConstrainColormapIndex(image,3UL-((*p >> 4) & 0x03));
          SetPixelIndex(indexes+x+1,index);
          index=ConstrainColormapIndex(image,3UL-((*p >> 2) & 0x03));
          SetPixelIndex(indexes+x+2,index);
          index=ConstrainColormapIndex(image,3UL-((*p) & 0x03));
          SetPixelIndex(indexes+x+3,index);
          p++;
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      (void) SyncImage(image);
      break;
    }
    case 4:
    {
      /*
        Read 4-bit PDB image.
      */
      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);
        for (x=0; x < (ssize_t) image->columns; x+=2)
        {
          index=ConstrainColormapIndex(image,15UL-((*p >> 4) & 0x0f));
          SetPixelIndex(indexes+x,index);
          index=ConstrainColormapIndex(image,15UL-((*p) & 0x0f));
          SetPixelIndex(indexes+x+1,index);
          p++;
        }
        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;
        status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
          image->rows);
        if (status == MagickFalse)
          break;
      }
      (void) SyncImage(image);
      break;
    }
    default:
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  }
  pixels=(unsigned char *) RelinquishMagickMemory(pixels);
  if (EOFBlob(image) != MagickFalse)
    ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
      image->filename);
  if (pdb_info.number_records > 1)
    {
      char
        *comment;

      int
        c;

      register char
        *p;

      size_t
        length;

      num_pad_bytes = (size_t) (comment_offset - TellBlob( image ));
      while (num_pad_bytes--) ReadBlobByte( image );

      /*
        Read comment.
      */
      c=ReadBlobByte(image);
      length=MaxTextExtent;
      comment=AcquireString((char *) NULL);
      for (p=comment; c != EOF; p++)
      {
        if ((size_t) (p-comment+MaxTextExtent) >= length)
          {
            *p='\0';
            length<<=1;
            length+=MaxTextExtent;
            comment=(char *) ResizeQuantumMemory(comment,length+MaxTextExtent,
              sizeof(*comment));
            if (comment == (char *) NULL)
              break;
            p=comment+strlen(comment);
          }
        *p=c;
        c=ReadBlobByte(image);
      }
      *p='\0';
      if (comment == (char *) NULL)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      (void) SetImageProperty(image,"comment",comment);
      comment=DestroyString(comment);
    }
  (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.