React.js Security Best Practices

Carefully built and well-functioning security systems in web applications help businesses to stand strong and establish trusting relationships with their customers. Security systems prevent sensitive data leaks, help companies maintain their reputation and minimize losses.

Unfortunately, some businesses overlook the importance of security in their apps and run into long-lasting negative consequences. According to Check Point Software’s Security Report, “87% of organizations have experienced an attempted exploit of an already-known, existing vulnerability” in 2020.

Many companies try to minimize security weaknesses. For this, they search for reliable IT companies with extensive app development expertise and use the most effective and time-tested technologies for building their web applications. One of these technologies is React.js.

In this article, we explain why to choose React.js for building your web application and how to secure React apps.

React.js Popularity and Why to Choose It

React.js is the second most popular JavaScript framework for web development according to StackOverflow’s latest developer survey. It’s a powerful solution for building dynamic and interactive user interfaces. With React.js web developers can create large web applications with fast performance and simple scalability. react security

The main features that make React.js a preferred technology for web development are:

reusable components for consistent app look and facilitated app development;
virtual DOM which allows fast web page rendering and improves app performance;
high abstraction layer that makes app development simple even for React.js beginners;
Flux – a Facebook architecture for simple data flow management in React.js apps;
Redux – a state container that organizes React.js apps, making them consistent and easy to test solutions;
a wide range of development tools, extensions, and compatible libraries.

Stackshare states that React.js has 168.2K stars on GitHub with over 33.8K GitHub forks. More than 9600 companies use React.js in their tech stacks, including Uber, Facebook, Netflix, Airbnb, Pinterest, Instagram, and many others.

Why is it Important to Follow React.js Security

Any business web app involves extensive data exchange and connection to various sources. This helps businesses compete in the market and effectively provide services to their customers. On the downside, this high connectivity makes web apps prone to a wide range of security flaws and data breaches.

When building their web apps with React.js, web developers have to keep in mind that React.js has no default security settings. Therefore, they need to know how to handle the most widespread security issues that may appear in web applications.

The most common React.js vulnerabilities include:

dangerous URL schemes;
broken authentication;
Server-side rendering;
SQL Injections;
Zip Slip;
Cross-Site Scripting (XSS).

React.js Security Vulnerabilities and Solutions

Let’s have a look at the most common React.js vulnerabilities and best practices to prevent them.

Dangerous URL Schemes

Links to other resources become dangerous when hackers add malicious code that starts with JavaScript to URLs. When a user clicks on a link, they activate the script in a browser. React.js app security doesn’t prevent the use of links without “HTTP:” or “HTTPS:” protocols and has no features to prevent potential threats.

To avoid JavaScript in their links, web developers can:

make links start with whitelisted protocol and display HTML entities on a browser;
eliminate URL input from the users e.g. use a YouTube video ID instead of its link;
implement third-party tools to sanitize all the input links.

Broken Authentication

The insecure connection between the web client and the server-side leads to broken authentication and user authorization issues. Hackers can interfere with the authentication and authorization processes and spoil user account data, passwords, session tokens, and other entities. react js security

The most widespread React.js security risk factors related to broken authentication include:

exposing session IDs in the URL;
simple or easy-to-predict login credentials;
session IDs and passwords transmitted with unencrypted connections;
session fixation attacks;
sessions that don’t get invalidated after a user logs out, and others.

To protect the HTTP basic authentication protocols, web developers need to:

determine if the domain “WWW” header has a real attribute which helps to avoid mismatches in user IDs and their passwords;
use proper authentication methods, e.g. make sure that a web app responds with a 401 status error page in case of failed authentication;
implement multi-factor authentication;
introduce cloud-native authentication, e.g. Google Cloud Identity Platform or Azure Active Directory;
implement password checks for strengths and weaknesses.

Server-Side Rendering

Many web apps utilize server-side rendering when they display their web pages and content to the users. Server-side rendering has many advantages. It improves app performance, makes webpage loading faster, and ensures consistent SEO performance. Although, this type of page rendering can involve some security challenges.

When rendering an initial state of a web page with Redux, web developers can generate a document variable from a JSON string looking like this:

The JSON.stringify() can be a risky method as it converts any given data into a string and displays it on a web page. As a result, attackers can insert some malicious code inside the JSON string and eventually take control of a web app or its data.

To tackle this vulnerability, web developers need to:

often perform code reviews and check the data that appears in JSON.stringify();
utilize serialize-JavaScript NPM module to avoid rendering JS

React.js Security Guide: Threats, Vulnerabilities, and Ways to Fix Them