#vulnerable code 
                                @Override
    public void intercept(FixedInvocation inv) {
        if (!config.isConfigOK()) {
            inv.invoke();
            return;
        }

        SsoShiroBridge ssoShiroBridge = JbootShiroManager.me().getSsoShiroBridge();
        if (ssoShiroBridge != null && ssoShiroBridge.isSsoCallBackRequest(inv.getController())) {
            ssoShiroBridge.subjectLogin(inv.getController());
        }

        AuthorizeResult result = JbootShiroManager.me().invoke(inv.getActionKey());

        if (result == null || result.isOk()) {
            inv.invoke();
            return;
        }

        int errorCode = result.getErrorCode();

        ShiroErrorProcess shiroErrorProcess = JbootShiroManager.me().getShiroErrorProcess();
        switch (errorCode) {
            case AuthorizeResult.ERROR_CODE_UNAUTHENTICATED:
                shiroErrorProcess.doProcessUnauthenticated(inv.getController());
                break;
            case AuthorizeResult.ERROR_CODE_UNAUTHORIZATION:
                shiroErrorProcess.doProcessuUnauthorization(inv.getController());
                break;
            default:
                inv.getController().renderError(404);
        }
    } 
                            #location 25 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public void intercept(FixedInvocation inv) {
        if (!config.isConfigOK()) {
            inv.invoke();
            return;
        }

        SsoShiroBridge ssoShiroBridge = JbootShiroManager.me().getSsoShiroBridge();
        if (ssoShiroBridge != null && ssoShiroBridge.isSsoCallBackRequest(inv.getController())) {
            ssoShiroBridge.subjectLogin(inv.getController());
        }

        AuthorizeResult result = JbootShiroManager.me().invoke(inv.getActionKey());

        if (result == null || result.isOk()) {
            inv.invoke();
            return;
        }

        ShiroErrorProcess shiroErrorProcess = JbootShiroManager.me().getShiroErrorProcess();
        shiroErrorProcess.doProcessError(inv, result.getErrorCode());

    }