file._isSymbolicLink = function() {
  var filepath = path.join.apply(path, arguments);
  return fs.lstatSync(filepath).isSymbolicLink();
};
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.