Javascript Injection Using Nightwatch JS

JavaScript injection attacks are one of the most common ways that hackers exploit web applications. These attacks involve inserting malicious code into input fields on web forms, which can then execute in the user's browser and compromise their data. In this article, we will show you how to use Nightwatch.js to write tests that ensure a form is not susceptible to JavaScript injections.

Prerequisites:

Before you get started, you'll need to have a basic understanding of Nightwatch.js and JavaScript. You'll also need to have a web application with a form that accepts user input.

Writing the Test:

To start, let's create a new test file called test_form_injection.js. This test will simulate a user entering JavaScript code into a form and verifying that the code does not execute in the user's browser.

module.exports = {
  'Test form for JavaScript injection': function (browser) {
    browser
      .url('https://yourapp.com/login')
      .waitForElementVisible('body')
      .setValue('input[name="username"]', '<script>alert("Hello, world!");</script>')
      .setValue('input[name="password"]', 'password123')
      .click('button[type="submit"]')
      .assert.urlEquals('https://yourapp.com/login')
      .assert.containsText('body', 'Invalid username or password')
      .execute(() => {
        return window.alerts;
      }, [], function(result) {
        browser.assert.equal(result.value, null, 'Expected no alert to be displayed after form submission');
      })
      .end();
  }
};

In this test, we're simulating a user entering the JavaScript code < script >alert("Hello, world!"); into the "username" field. If our form is vulnerable to JavaScript injection, this code would execute in the user's browser when the form is submitted and display an alert dialog box with the message "Hello, world!". However, because we've properly sanitized the code, the form should not execute the JavaScript code in the user's browser and should display an error message instead. We're also using the .execute() command to run a JavaScript function in the browser that returns the value of the alerts variable. We then use the assert.equal() command to verify that the value of alerts is null, which indicates that no alert dialog was displayed after the form submission.

Running the Test:

To run this test, save it to a file named test_form_injection.js and then run the following command:

nightwatch test_form_injection.js

If the test passes, then your form is properly sanitized and is not susceptible to JavaScript injection attacks. If the test fails, then you'll need to go back and review your form validation and sanitization code to ensure that it properly filters out malicious JavaScript code.

In this article, we've shown you how to use Nightwatch.js to write tests that ensure a form is not susceptible to JavaScript injections. By running these tests regularly during your development process, you can ensure that your application is secure and that user input is properly sanitized and validated. Remember, it's always better to prevent vulnerabilities before they become exploits.