static MagickBooleanType DecodeImage(Image *image,const size_t compression,
  unsigned char *pixels)
{
  int
    count;

  register ssize_t
    i,
    x;

  register unsigned char
    *p,
    *q;

  ssize_t
    y;

  unsigned char
    byte;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(pixels != (unsigned char *) NULL);
  (void) ResetMagickMemory(pixels,0,(size_t) image->columns*image->rows*
    sizeof(*pixels));
  byte=0;
  x=0;
  p=pixels;
  q=pixels+(size_t) image->columns*image->rows;
  for (y=0; y < (ssize_t) image->rows; )
  {
    if ((p < pixels) || (p >= q))
      break;
    count=ReadBlobByte(image);
    if (count == EOF)
      break;
    if (count != 0)
      {
        /*
          Encoded mode.
        */
        count=(int) MagickMin((ssize_t) count,(ssize_t) (q-p));
        byte=(unsigned char) ReadBlobByte(image);
        if (compression == BI_RLE8)
          {
            for (i=0; i < (ssize_t) count; i++)
              *p++=(unsigned char) byte;
          }
        else
          {
            for (i=0; i < (ssize_t) count; i++)
              *p++=(unsigned char)
                ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
          }
        x+=count;
      }
    else
      {
        /*
          Escape mode.
        */
        count=ReadBlobByte(image);
        if (count == 0x01)
          return(MagickTrue);
        switch (count)
        {
          case 0x00:
          {
            /*
              End of line.
            */
            x=0;
            y++;
            p=pixels+y*image->columns;
            break;
          }
          case 0x02:
          {
            /*
              Delta mode.
            */
            x+=ReadBlobByte(image);
            y+=ReadBlobByte(image);
            p=pixels+y*image->columns+x;
            break;
          }
          default:
          {
            /*
              Absolute mode.
            */
            count=(int) MagickMin((ssize_t) count,(ssize_t) (q-p));
            if (compression == BI_RLE8)
              for (i=0; i < (ssize_t) count; i++)
                *p++=(unsigned char) ReadBlobByte(image);
            else
              for (i=0; i < (ssize_t) count; i++)
              {
                if ((i & 0x01) == 0)
                  byte=(unsigned char) ReadBlobByte(image);
                *p++=(unsigned char)
                  ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
              }
            x+=count;
            /*
              Read pad byte.
            */
            if (compression == BI_RLE8)
              {
                if ((count & 0x01) != 0)
                  (void) ReadBlobByte(image);
              }
            else
              if (((count & 0x03) == 1) || ((count & 0x03) == 2))
                (void) ReadBlobByte(image);
            break;
          }
        }
      }
    if (SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,image->rows) == MagickFalse)
      break;
  }
  (void) ReadBlobByte(image);  /* end of line */
  (void) ReadBlobByte(image);
  return(MagickTrue);
}

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.