  _read(n) {
    if (this._channel._waitChanDrain) {
      this._channel._waitChanDrain = false;
      if (this._channel.incoming.window <= WINDOW_THRESHOLD)
        windowAdjust(this._channel);
    }
  }
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.