  function onError(err) {
    const which = (this === client ? 'client' : 'server');
    assert(false, msg(`Unexpected ${which} error: ${err}`));
  }
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.