      def process_preflight(env)
        result = Result.preflight(env)

        resource, error = match_resource(env)
        unless resource
          result.miss(error)
          return {}
        end

        return resource.process_preflight(env, result)
      end
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.