Client.prototype.end = function() {
  if (this._sock
      && this._sock.writable
      && this._sshstream
      && this._sshstream.writable)
    return this._sshstream.disconnect();
  return false;
};
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.