#fixed code
                                public void execute(Integer status, String body) {

        RequestContext ctx = RequestContext.getCurrentContext();

        String response;
        if (helper.json().isJson(body)) {
            response = helper.json().parse(body);

            helper.call().response().header().add("Content-Type", "application/json");
        } else {

            response = body;

            helper.call().response().header().add("Content-Type", "text/plain");
        }

        helper.call().response().setBody(response);

        ctx.setSendZuulResponse(false);
        ctx.setResponseStatusCode(status);

        TraceContextHolder.getInstance().getActualTrace().trace(ConstantsInterceptors.GLOBAL_MOCK_INTERCEPTOR_LOCALIZED, response);
    }
#vulnerable code 
                                public void execute(Integer status, String body) {

        Helper helper = new HelperImpl();
        RequestContext ctx = RequestContext.getCurrentContext();

        String response;
        if (helper.json().isJson(body)) {
            response = helper.json().parse(body);

            helper.call().response().header().add("Content-Type", "application/json");
        } else {

            response = body;

            helper.call().response().header().add("Content-Type", "text/plain");
        }

        helper.call().response().setBody(response);

        ctx.setSendZuulResponse(false);
        ctx.setResponseStatusCode(status);

        TraceContextHolder.getInstance().getActualTrace().trace(ConstantsInterceptors.GLOBAL_MOCK_INTERCEPTOR_LOCALIZED, response);
    } 
                            #location 10 
                            #vulnerability type NULL_DEREFERENCE