In this article, I want to share my 5 tips for frontend development security. These practices have been honed through years of experience, adaptation, and staying ahead of the curve in an industry that constantly pushes the boundaries of innovation. I’ve been fortunate to cross paths with numerous talented individuals who have profoundly influenced my growth as a person and developer. Having spent a decade in the software development field, with a strong foundation in full stack engineering, the last half of my career has been mostly dedicated to frontend development. During this time, I’ve discovered and learned valuable insights and techniques to build more secure applications.

By implementing the following 5 measures, developers can enhance code quality and mitigate security risks. Join me as we delve in software development security and discover key practices for building secure applications in the face of constant change.

1. Use a JavaScript Linter

Maintaining consistency in development patterns is not only beneficial for keeping teams aligned, but it also helps to prevent common failures resulting from distractions or lack of knowledge.

One of the most straightforward and uncomplicated methods to prevent JavaScript security concerns involves utilizing code linting. Linters function as static code analysis utilities that examine your code for stylistic errors, programmatic flaws, and recognized security vulnerabilities, all happening before runtime.

JSHint, JSLint, and ESLint are three widely recognized linters specifically designed for JavaScript. Additionally, IDEs like Visual Studio Code provide built-in JavaScript linting capabilities that can be customized with plugins.

✋ Important:
Code reviews play a vital role in software development as they provide an essential checkpoint for ensuring code quality, consistency, and reliability. Through systematic examination of code by peers, potential bugs, logical errors, and design flaws can be identified and rectified before they make their way into production. Code reviews not only improve the overall quality of the software but also facilitate knowledge sharing, foster collaboration among team members, and help enforce best practices in coding. By incorporating code reviews into the development process, organizations can enhance code maintainability, minimize technical debt, and ultimately deliver robust and high-performing software solutions to their users.

2. Audit your NPM Packages

These days, developers heavily rely on npm packages to build their apps. Rather than reinventing the wheel, there are already battle-tested solutions available and ready to use, however, many times these packages contain vulnerabilities, which is why npm audit comes in handy.

When you use the npm install command to install a package, npm audit is automatically executed. Additionally, you have the option to manually run npm audit on your locally installed packages. This allows you to perform a comprehensive security audit of the package and generate a detailed report that identifies any dependency vulnerabilities and, if applicable, provides suggested patches.

1. On the command line, navigate to your package directory by typing cd path/to/your-package-name and pressing Enter.

2. Ensure your package contains package.json and package-lock.json files.

3. Type npm audit and press Enter.

4. Review the audit report and run recommended commands or investigate further if needed.

✋ Caution:
While packages are typically open-source, it is important not to select a package solely based on its title. Blindly relying on package titles can be misleading. Instead, it is crucial to consider factors such as the package’s supporters, download count, and whether the project is actively maintained. Choosing a reputable package that has undergone rigorous scrutiny is far superior to choosing a package with little recognition or support. Sometimes, packages are simply discontinued and should be used with caution.

3. Validate User Input

JavaScript, by its inherent nature, is often considered unsafe as it runs on the client machine. However, modern implementations make efforts to mitigate certain associated risks. Therefore, while we should not solely rely on JavaScript measures, it is imperative for the backend to also implement security measures.

HTML5 forms are equipped with convenient form validation attributes, including required, min, max, type, and more. These attributes allow you to validate user data and display error messages without the need for JavaScript on the client side. Additionally, the pattern attribute in HTML allows you to validate input values using Regular Expressions.

Before submitting data to the server, it is important to ensure all required form controls are filled out, in the correct format. This is called client-side form validation.

You can also consider battle-tested libraries for input validation such as validator.js.

4. Escape User Input

Escaping or encoding in JavaScript is a crucial safety measure to protect against security vulnerabilities, particularly when handling user input or dynamically generating HTML, URLs, or other content.

Escaping involves converting special characters or sequences into their safe counterparts, ensuring they are interpreted as literal characters rather than having special meaning in the given context. This prevents issues like cross-site scripting (XSS) attacks, where malicious scripts can be injected and executed on a webpage.

Whenever feasible, go with typical libraries/frameworks such as React, Angular, etc. because they prioritize security by implementing robust measures to safeguard your web applications. They often come with built-in security features. This ensures a strong foundation for developing secure applications and helps protect against potential threats and attacks.

In React, for instance, React DOM inherently safeguards any embedded values within JSX by default before rendering them. As a result, it guarantees that you cannot inject anything that is not explicitly stated in your application. All content undergoes conversion to a string format prior to rendering, ensuring an added level of security. This helps prevent XSS (cross-site-scripting) attacks.

Whether you are using a library/framework or simply a vanilla app, you can also consider DOMPurify. It is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG.

5. Optimize Your Code: Bundle and Minify

As you may be aware, JavaScript executes on the client side, giving potential attackers full access and control over it. However, by bundling and minifying JavaScript, we can raise the bar for potential attackers, impeding their efforts to exploit it.

While Webpack stands out as a highly popular tool for these objectives, there exists a myriad of alternatives at your disposal as well like Gulp and Parcel.

6. Use a DAST Scanner (BONUS)

By incorporating a DAST scanner into your development lifecycle, developers can save valuable time and effort, ensuring that security vulnerabilities are identified and addressed early on.

A Dynamic Application Security Testing (DAST) scanner actively examines a running application for vulnerabilities and promptly generates automated alerts upon detecting any weaknesses that could potentially lead to attacks such as SQL injections, Cross-Site Scripting (XSS), and other similar exploits. One notable tool in this domain is Probely which offers a comprehensive DAST scanning solution. By leveraging Probely, developers can streamline their security testing processes and gain valuable insights to enhance the resilience of their API’s or applications.

Conclusion

Implementing these powerful frontend security measures by taking advantage of automation and cost-effectiveness, you can significantly enhance the security of your web applications. These measures not only ensure a safer environment for your applications but also contribute to the overall efficiency and productivity of your development team.