Neos\Neos\Controller\Module\User\UserSettingsController::updateAccountAction PHP Method

    public function updateAccountAction(array $password = array())
    {
        $user = $this->currentUser;
        $password = array_shift($password);
        if (strlen(trim(strval($password))) > 0) {
            $this->userService->setUserPassword($user, $password);
            $this->addFlashMessage('The password has been updated.', 'Password updated', Message::SEVERITY_OK);
        }
        $this->redirect('index');
    }