How to Secure ReactJS App? ReactJS Security Best Practices to Follow

Quick Summary:

Although not visible to the human eye, React security vulnerabilities can be deadly to your web application. JavaScript has a lengthy history of being related to common security vulnerabilities. Reactjs is no different. Some of the javascript libraries’ components have security flaws that have resulted in millions of downloads, some of which can be deadly to your web application. This blog will show you how to quickly fix Reactjs Security Vulnerabilities, reducing the likelihood of security problems collecting in your online application over time.

React is a front-end JavaScript library for creating user interface (UI) components that are free and open-source. React, created and maintained by Facebook, has a prominent developer and business community. ReactJS offers a solution that may be used to build single-page or mobile apps.

It employs the JSX syntax, which includes HTML quotes and an HTML tag syntax application for displaying specified subcomponents. This is highly beneficial in supporting the creation of machine-readable codes while also combining components into a single-time verified file.

  • Reactjs has quickly become popular. It has 183K stars and 37.3K Forks on GitHub, and 10,499,785 sites are currently using Reactjs
  • React is at most loved framework with 40.14%, according to StackOverflow’s developer survey 2021


    • According to js’ state, react is on top in terms of usage in 2021

reactjs usages stats

  • As per the Synk report, about two out of three security vulnerabilities found in React core modules are related to Cross-site Scripting (XSS). Such vulnerabilities only occur when using any affected modules, such as the react-dom server side.

Why use ReactJS

The most widely used JavaScript framework for web development is Reactjs. React is a robust framework for creating dynamic and interactive user interfaces. You may hire web app development company to design web applications that are quick to load and scale.

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The following are some of the critical features that make react.js a good choice for web development:

  • Reusable components
  • Uses Virtual DOM
  • High Abstraction layer
  • Enhanced Performance
  • Uses Flux
  • Supports REDUX
  • Supports a wide range of development tools, extensions, and compatible libraries

Features of React.js for Web Development

Most Common Security Threat to a React Application

Because Reactjs is such an essential element of the tech stack, consider your company’s inescapable reactjs security risks and ramifications. And, because React.js is updated and improved regularly, the list of react security vulnerabilities is extensive. We’ll go over the six most prevalent cyber assaults on react.js in this part. Let’s take a closer look at each of them:

Security threat react application

Cross-site Scripting (XSS)

Cross-site Scripting is the first of several security issues with reactjs. An injection of a malicious script into the code of a web application is referred to as XSS. This script gets picked up by the browser and interpreted as authentic. The malicious code is then executed as part of an app. The following diagram depicts the process of an attacker injecting XSS code to steal a user’s or visitor’s session cookies:

Cross-site Scripting

A successful XSS attack might allow the attacker to steal the user’s credentials, take sensitive data from the app’s pages, transmit the request to the server, and more.

Reactjs, like most modern frameworks, has an XSS defence built-in. SQL Injection is frequently confused with SQLi. Even though they both suggest malicious code injection, they are not the same thing. On the other hand, XSS makes the user susceptible, whereas SQLi attacks the application. There are in-built solutions for protecting XSS attacks. Regrettably, they aren’t entirely adequate. XSS is the most popular JavaScript attack to this day.

Let’s look at the Samy worm, which exploited the MySpace XSS vulnerability, for a better understanding. One of the most rapidly spreading viruses in history.

import React, {useState} from 'react';
import createDOMPurify from ‘dompurify’;
function App(){
 const [text, setText] = useState(‘’);
 function updateText(e){
  return (
      <input onChange={updateText} type="text" value={text} />
      <div dangerouslySetInnerHTML={{__html: createDOMPurify(text)}}/ >
export default App;

Also Read: – Best React UI Framework You Should Know In 2024

Broken Authentication

An inadequate or insufficient authorization is another major problem with React.js applications. Session IDs being exposed in URLs, attackers discovering easy and predictable login details, the unencrypted transmission of credentials, valid sessions lasting after logout, and other session-related aspects are all hazards linked with broken authorization. As a result, attackers may gain access to user credentials and conduct brute force assaults.

SQL Injection

SQL Injection sometimes referred to as SQLi, is a standard web application attack. The cybercriminal aims to use logical database manipulation to gain sensitive data that should not be displayed. Attackers attempt to gain access to sensitive information to obtain phone numbers, payment information, and other information.

The attackers can use this response react security strategy to regulate access to the server, pull data, and modify database values. Hackers can potentially erase data in addition to altering it.

Consider the following scenario, in which the owner is the current user-ID.

string query = "SELECT * FROM logondata WHERE owner = "'"

+ empID + "' AND empName = '"

+ EmpName.Text + "'";

The following query gets generated by combining both the employee ID and employee name.

SELECT * FROM logondata

WHERE owner =

AND empName = ;

The issue here is that the main code uses the concept of concatenation, which aids in the combination of those data. As the employee name, the attackers can use a string like 'empName' or 'x' = 'x'. As a result, the statement returns True for all table values. As a result, the following question becomes:

SELECT * FROM log data

WHERE owner = 'Adien.'

AND empName = 'name' OR 'x' = 'x';

Zip Slip

Zip Slip is the third item on the list of reacting security concerns. In React applications, a vulnerability is known as “zip-slip” includes exploiting the feature that allows users to upload zip files.

If the archive used to unpack the zip file is not secure, the attackers could unzip the uploaded files outside of the given directory and obtain access to the file.

Arbitrary Code Execution

ACE is another one of the most significant security vulnerabilities. ACE is a software or hardware security vulnerability that allows arbitrary code execution. The capacity of an attacker to execute arbitrary code on a target process is known as arbitrary code execution (ACE). An arbitrary code execution exploits when a product or software is abused using this vulnerability. This vulnerability is particularly hazardous because it can arise in some public products, exposing all people who utilize it. The WannaCry ransomware outbreak is the finest example of how these attacks work.

XML External Entity Attack (XXE)

XML External Entity Attack

XXE is another one of the react frontend security problems. Web applications that use XML (Extensible Markup Language), a text-based language for storing and organizing data in a web app, are vulnerable to XXE assaults. An XML parser is required for converting XML into usable code. These attacks frequently target such parsers, and an attacker can use XXE to launch a CSRF or DDOS assault. The fundamental problem is that XML parsers are vulnerable to these attacks by default. Thus, it’s up to your development team to protect yourself.

Some of the most common response security flaws are listed above. Now let’s look at the vulnerabilities connected to respond in particular. Js

Reactjs Security Vulnerabilities & Solutions

When it comes to online applications, the most prevalent cyber attacks include XSS, Broken-authentication, SQLi, Zip-slip, Arbitrary Code Execution, and XXE, as stated above. Below we will discuss security issues related to React.js.

Vulnerabilities Specific to ReactJS & their Solutions

The following vulnerabilities should be avoided while developing a React-based application.

  • Server-side rendering
  • Dangerous URL Scheme
  • Escape Hatches
  • Dangerous SetInner HTML

Reactjs Security Vulnerabilities

Server-side Rendering

SSR is one of React’s most well-known benefits (Server-side rendering). This feature guarantees a faster page load time, improved performance, and ease of SEO integration. Regrettably, this puts React apps vulnerable to hacking. To set an initial app state, most React apps use Redux, which leverages JSON, a lightweight data-interchange standard.

This is risky because “JSON.stringify” does not recognize sensitive data or XSS code. Although the method above also protects against simple XSS attacks, it is far from ideal.

  • Use regular-expression
  • Use the serialize-javascript package

Also Read: – Top React Performance Optimization Tips in 2024

Dangerous URL Scheme

Malicious code can enter your React application using URLs without the “HTTP:” or “HTTPS:” protocol. It’s safe to use if the URL is hardcoded. However, if a user provides it, it may be vulnerable to React XSS.

Unfortunately, neither the security features of React.js nor the built-in safeguards against potential risks restrict the use of such links during development. This implies that it is up to your development team to keep them safe.


When entering data, avoid using URLs. For example, create a program that accepts YouTube video IDs rather than YouTube video URLs.

If the method above isn’t practicable, sanitize these potentially harmful links with proven third-party solutions like the Sanitize URL NPM package. Ascertain that every member of your development team follows the same sanitation code.

Dangerous SetInner HTML

Developers are occasionally required to render HTML code from unreliable sources. Assigning it to the inner HTML attribute directly is the most straightforward approach to rendering it in a browser. React.js restricts its use by using the “dangerouslySetInnerHTML” property because it can lead to XSS issues.

The function of “dangerouslySetInnerHTML” is to notify a developer that the code assigned to it may be insecure. Unfortunately, this attribute does not guarantee the security of the code and renders all data, whether benign or harmful. Furthermore, developers are unlikely to use this feature without first reading the documentation.

  • When sanitizing dynamic values assigned to the “dangerouslySetInnerHTML” property, always use DOMPurify. Create a security component that encapsulates this behaviour and encourages programmers to use it
  • Always use user-generated properties when calling the “createElement” API

Escape Hatches

One of the main benefits of React is that it eliminates the need for developers to enter data into the browser DOM to render components manually. However, there are times when developers want direct access to DOM elements.

React includes escaping hatches such as “findDOMNode” and “createRef” for such cases. The application can modify the element directly without going via React because an escape hatch returns the native DOM elements with their complete API. This could result in an XSS flaw.

  • The only text should be output, not HTML code
  • Use correct DOM APIs to build HTML nodes when a direct output is required
  • Before adding data to the page, use DOMPurify to clean it up

Also Read: – Best React Developer Tools

14 React Security Best Practices

Here are some tips for securing react apps. These react security solutions will help resolve the issues that might arise while securing the react application.

React security best practices

Securing Against DDoS Attack

Typically, this type of security vulnerability occurs when the program has some flaws in concealing the IPs of services or when the app isn’t secure enough.


  • Rate limits on APIs: You can limit the number of requests from a specific source to a specific IP. Axios has a complete package named Axios-rate-limit for limiting the rate of APIs
  • You can use the API to add app-level restrictions
  • Always make calls from the server, not from the client
  • Add some validation to the app layer to make it safer

Default XSS Protection with Data Binding

To place data in your elements, you can utilize the JSX data-binding syntax { }. While utilizing default data binding with curly brackets { }, React will automatically escape values to defend against XSS attacks. It’s important to note that this protection only applies to text content, not HTML properties.


Use this:


Avoid dynamic attributes values without custom validation

Don’t use this:

<form action={data}>…

You can also use reactjs content security policies as the last line of defence against XSS. If all other XSS prevention fails, CSP allows developers to control various things, such as loading external scripts and executing inline scripts. To deploy CSP, developers need to include an HTTP response header called Content-Security-Policy with the value carrying the policy.

default-src 'self'; script-src 'self'; object-src 'none'; frame-src 'none'; base-uri 'none';

Rendering HTML

Using dangerouslySetInnerHTML, you can directly enter HTML into a displayed DOM node. Any text that is introduced in this manner must be sanitized first. Before putting any values into the dangerouslySetInnerHTML prop, use a sanitization library like dompurify.


Use dompurify when inserting HTML into DOM.

Import purify from “dompurify”;
< div dangerouslySetInnerHTML={{ __html:purify.sanitize (data)}}/ >

Securing HTTP Authentication

Suppose your app offers an authentication function that allows users to log in or create accounts. In that case, you should ensure it’s safe because client-side authentication and authorization are often vulnerable to security issues that can compromise the app’s protocols.


Most prominently, you would’ve used one of the following methods to add authentication:

Injection JSON State

JSON data is frequently sent in conjunction with server-side rendered React pages. To avoid injection attacks, make sure to escape HTML significant values. To avoid injection attacks, always escape characters with a beginning value.

window.__PRELOADED_STATE__ =   ${JSON.stringify(preloadedState).replace( /</g, '\\u003c')}

Configuring Security Linters

Install Linter settings and plugins to detect and advise on security vulnerabilities in your code automatically. Using a library like husky, set up a pre-commit hook that fails if security-related Linter concerns are identified. When new vulnerabilities in the version you’re using are discovered, you can use synk to update to a new version automatically. To discover security vulnerabilities in a codebase, use the ESLint React security config.

Avoid Dangerous Library Code

The library code is routinely used to perform potentially dangerous actions, such as directly inserting HTML into the DOM. Review library code or use linters to find hazardous uses of React’s security mechanisms.

Also Read: – Top React Chart Libraries to Visualize your Data in 2024


Avoid libraries with a history of putting people in danger. SetInnerHTML, innerHTML, unvalidated URLs, and other unsafe patterns exist. Use security Linters on your node modules folder to detect harmful patterns in your library code.

Detecting vulnerable React Version

Because the React library has had a few high-severity vulnerabilities in the past, it’s a good idea to stay up to date with the most recent version. To prevent vulnerable versions, use npm outdated to see the newest versions of reacting and react-dom.

Adding end-to-end Encryption

The global average cost of a data breach, according to Statista, is $4.24 million. In most situations, the data breach is triggered by online apps failing to offer End-to-End encryption. As an engineering lead, you should secure the security of your react application by implementing end-to-end encryption. This encryption is used by your application to protect the communication between its users. Transferring private information to third parties is not a good idea.

End-to-end encryption is a time-saving feature:

  • Encrypt data with public and private keys despite the complex structure
  • Use asymmetric algorithms such as RSA to encrypt the primary key
  • The symmetric AES technique was used to encrypt the transactions
  • Encryption libraries like encrptjs and cryptojs are beneficial for server-side and client-side encryption

Direct DOM Access

It’s preferable to avoid directly inserting material into DOM elements using the DOM. If you must inject HTML, sanitize it using dangerouslySetInnerHTML and dompurify before doing so.


Import purify from “dompurify”;
< div dangerouslySetInnerHTML={{ __html:purify.sanitize (data)}}/ >

To directly inject content using innerHTML and comparable attributes or methods, avoid utilizing refs and findDomNode() to access rendered DOM nodes.

Don’t do this:

this.myRef.current.innerHTML = attackerControlledValue;

Securing Against Libraries & Components

There is always a risk associated when using third-party libraries, modules, or APIs in your React app. Sure, they aid in the speedy creation of features, but who knows if their own set of security problems could cause your react app to crash.


  • Attempt to upgrade these libraries manually to the most recent secure and stable version
  • Older versions of the react secure component should be patched with newer versions
  • Before incorporating any libraries into your project, make a quick check for security flaws. While you’re looking for flaws, see whether any potential fixes are offered

Also Read: – Top React Native UI Components Libraries

Insecure Deserialization

If you recall our conversation on how to defend your react web application from XXE, you’ll recall that data serialization leads to specific react js security issues. However, the deserialization of objects injected by an authorized user or an attacker results in the remote execution of programs, which might cause an application’s behaviour to change.


  • Conduct integrity checks to ensure that no malicious objects are injected
  • Think about code segregation
  • Before the unauthorized construction of code objects, impose rigorous deserialization limitations

Security Against Broken Authentication

Invalid authentication processes, incorrect implementation, and failing authentication functionalities can lead to credential compromise or exploitation in your web application. Automated brute force assaults or, in some situations, authentication failure, may result from credential stuffing.


  • Multi-factor authentication should be implemented
  • Recover the passwords
  • Connect the APIs
  • Secure access will be provided via cloud-native authentication technologies

Validating URL Parsing

When linking material with the anchor tag a> and URLs, be wary of attackers introducing payloads that are prefixed with JavaScript. Always validate the URL using the HTTP or HTTPS protocols to avoid malicious script insertion via URL.

function validateURL(url) {
	const parsed = new URL(url)
	return ['https:', 'http:'].includes(parsed.protocol)
<a href={validateURL(url) ? url : ''}>This is a link! </a>

The allowlist/blocklist function is another method for protecting your React application. Allowlist refers to a list of all the safe and accessible URLs. While a blocklist is a list of all potential risks that will be blocked if access is requested, a whitelist is a list of all potential dangers that will not be blocked. Because keeping track of all potentially hazardous connections can be challenging, it’s a good idea to allow only known sites and block everything else. Broken authentication, XSS, arbitrary code execution, and SQL Injection can all be prevented via URL validation.

The allowlist/blocklist function is another method for protecting your React application. Allowlist refers to a list of all the safe and accessible URLs. While a blocklist is a list of all potential risks that will be blocked if access is requested, a whitelist is a list of all potential dangers that will not be blocked. Because keeping track of all potentially hazardous connections can be challenging, it’s a good idea to allow only known sites and block everything else. Broken authentication, XSS, arbitrary code execution, and SQL Injection can all be prevented via URL validation.

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React Security Checklist

  • Disable any instruction-containing markup
  • With Jscrambler, you can keep reactjs safe
  • Idle timeout should be implemented
  • Use snippet libraries such as ES7 React, Redux, and others
  • Conduct Reactjs code audits, filtering all app inputs with whitelists
  • Use vulnerability scanners, a web app firewall, and serialize javascript NPM packages to improve app security
  • Examine your code for flaws and potentially hazardous code, such as URLs and HTML components
  • Appropriate authentication techniques should be used
  • Check for SQL injection in the database
  • Validate all API functions according to API Schema

React Security Checklist

Wrapping Up!

Many global corporations look for top React development companies to construct their web solutions. I hope this article has provided you with a clear picture of the most common React security vulnerabilities and the various checklists developers can use to solve them. Developers should be aware of the importance of application security for both the business and the users. You’ll have fewer typing options and more explicit code if you use React security practices. This list of React security best practices will guide you in the right direction and, in the long run, eliminate any future development issues.

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    Saurabh Barot

    Saurabh Barot, the CTO of Aglowid IT Solutions, leads a team of 50+ IT experts across various domains. He excels in web, mobile, IoT, AI/ML, and emerging tech. Saurabh's technical prowess is underscored by his contributions to Agile, Scrum, and Sprint-based milestones. His guidance as a CTO ensures remote teams achieve project success with precision and technical excellence.

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