                        failureRedirect: '/login/index.html' + req.body.origin + (req.body.origin ? '&error' : '?error'),
                        failureFlash:    'Invalid username or password.'
                    })(req, res, next);
                });

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.