MagickBooleanType ListThresholdMapFile(FILE *file,const char *xml,
  const char *filename,ExceptionInfo *exception)
{
  const char
    *alias,
    *content,
    *map;

  XMLTreeInfo
    *description,
    *threshold,
    *thresholds;

  assert( xml != (char *) NULL );
  assert( file != (FILE *) NULL );
  (void) LogMagickEvent(ConfigureEvent,GetMagickModule(),
    "Loading threshold map file \"%s\" ...",filename);
  thresholds=NewXMLTree(xml,exception);
  if ( thresholds == (XMLTreeInfo *) NULL )
    return(MagickFalse);
  (void) FormatLocaleFile(file,"%-16s %-12s %s\n","Map","Alias","Description");
  (void) FormatLocaleFile(file,
    "----------------------------------------------------\n");
  threshold=GetXMLTreeChild(thresholds,"threshold");
  for ( ; threshold != (XMLTreeInfo *) NULL;
          threshold=GetNextXMLTreeTag(threshold))
  {
    map=GetXMLTreeAttribute(threshold,"map");
    if (map == (char *) NULL)
      {
        (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
          "XmlMissingAttribute", "<map>");
        thresholds=DestroyXMLTree(thresholds);
        return(MagickFalse);
      }
    alias=GetXMLTreeAttribute(threshold,"alias");
    description=GetXMLTreeChild(threshold,"description");
    if (description == (XMLTreeInfo *) NULL)
      {
        (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
          "XmlMissingElement", "<description>, map \"%s\"",map);
        thresholds=DestroyXMLTree(thresholds);
        return(MagickFalse);
      }
    content=GetXMLTreeContent(description);
    if (content == (char *) NULL)
      {
        (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
          "XmlMissingContent", "<description>, map \"%s\"", map);
        thresholds=DestroyXMLTree(thresholds);
        return(MagickFalse);
      }
    (void) FormatLocaleFile(file,"%-16s %-12s %s\n",map,alias ? alias : "",
      content);
  }
  thresholds=DestroyXMLTree(thresholds);
  return(MagickTrue);
}

The product reads data past the end, or before the beginning, of the intended buffer.