9 Best Practices to Secure Your Node.js Applications

Quick Summary: Creating secure Node.js applications is a priority for developers. While it is a secure runtime environment, there might be some vulnerabilities that could compromise Node.js security. In this article, we have discussed the best practices for Node JS that will help to secure your applications. Keep reading to know these practices.

NodeJS is a shining star in backend development since it's a favorite choice for many developers. It is used by many global giant companies like Netflix, LinkedIn, and PayPal. According to Statista’s developer survey, it is the most used web framework, securing the first position.

But being popular also means it is on the hitlist of attackers. While Node.js is secure by design, often additional packages used through NPM can open some vulnerabilities. These vulnerabilities can allow an attacker to compromise the security of NodeJS applications.

You can protect your applications by following Node.js best practices. These practices will help you prevent security loopholes that could put your applications at risk. Keep reading to know these best practices and elevate your security posture.

Security Breaches Involve High Stakes, Avoid Them by Discovering Hidden Loopholes Eliminate the Risk

9 Best Practices to Secure Your NodeJS Applications

Is Node.js secure? Well, the answer isn’t straightforward because no technology is 100% secure. It is possible to exploit every technology with the right resources. While their developers design technologies to be secure and consider all aspects, there can be some weak spots that attackers can find and exploit.

Hence, keeping your Node.js application secure requires more effort than implementing a few security features. You must find out potential weaknesses of your application through vulnerability assessment to fill all the gaps. In addition, following the Node JS security best practices helps to contain the possible security risks significantly.

These best practices provide measures to enhance the overall security of your Node.js application by eliminating common security flaws. Let’s check out these best practices for NodeJS security below and ensure secure applications.

1. Avoid Running Node.js with a Root User

It seems an ordinary issue, but many developers fail to pay attention to this aspect. Executing NodeJS with root access and unlimited privileges can pose serious security challenges. Just imagine if the code your Node.js application executes with root access contains malicious commands or scripts that are processed without proper validation; it would compromise the application’s security.

Your server could get hacked if it’s running with a root user. Apart from this, an attacker could also exploit a vulnerability to breach NodeJS security. After this, the attacker will get a jackpot by getting full control of your machine with root access. Consequently, the attacker could wipe out your data or do other damage.

2. Ensure Input Validation to Prevent XSS Attacks

Input validation is a coding technique that ensures only valid data is passed for further processing. With this technique, you can check user-supplied data and ensure it meets the desired constraints and rules. Often, attackers exploit input validation flaws to carry out XSS or Cross-Site Scripting attacks.

The attackers can inject malicious JavaScript code into the front end and fool users into entering sensitive data. The application is forced to execute the code and the data is sent to the attacker. There are various methods to overcome this challenge like using xss-filters to encode output, HTML sanitization, implementing content-security policies, setting httpOnly flag, and more.

3. Handle Uncaught Exceptions to Prevent Loopholes

Exceptions indicate errors or failures that interrupt the normal functioning of an application. Mostly, developers write code to catch these exceptions and display relevant error messages. However, there could be some uncaught errors that may not have been handled correctly.

Usually, Node will print the existing stack trace in case of an uncaught exception. However, exceptions that are not handled can cause NodeJS security vulnerabilities. These exceptions can occur due to improper handlers or unnecessary resource allocation. You can get error alerts with “triggerUncaughtException” in the stack trace.

NodeJS EventEmitter could be useful in managing uncaught exceptions. It will emit the uncaught exception to the main event loop. By managing such exceptions, you can easily keep many kinds of Node JS security issues at bay.

4. Be Careful When Using the Eval Function

JavaScript code is provided as a string value to the “eval” function, and it is evaluated just like other code. Usually, you don’t need this function. However, it can be used to make your code more dynamic. The disadvantage of using “eval” is that an attacker can exploit it to execute malicious code.

The attacker can execute system-level commands using this function and could gain unauthorized access to the system. Since this function takes only string, it’s difficult to determine what input is provided to this function.

You can avoid using it to ensure NodeJS security. However, you will have to consider many details if you want to use it securely. Similarly, there are some other functions and modules you should avoid, like the execScript function, setTimeout function, and vm module, to ensure secure Node JS applications.

5. Disable “inspector” to Prevent DNS Rebinding

Node applications are debugged using the built-in “inspector” feature. It can be enabled using the “--inspector” switch. After this, a NodeJS process will listen for a debugging client. Since web applications make WebSocket and HTTP requests, they can also target the local debugger on the client side.

Usually, it is prevented by the same-origin policy of browsers, but an attacker can use a DNS rebinding attack to overcome this policy. The attacker can control the DNS server and application to manipulate the origin of the request, which seems to originate locally. By disabling this feature, you can prevent such attacks and mitigate Node JS security risks.

Harness the Power of Automated Scanning to Uncover Node.js Vulnerabilities Hunt Them Now

6. Limit the Size of Requests to Prevent DDoS Attacks

Node.js has a default limit of 5 MB for requests. However, large requests can put a strain on your server's computing resources. An attacker can take advantage of a few large requests to overwhelm your server and cause a DDoS attack.

You can avoid floods of requests from an attacker by reducing the default limit for requests. After this, your Node.js application will process smaller requests at a time. Also, any requests above the specified limit will be blocked. It could mitigate the risks of DDoS attacks.

7. Use Cookie Flags for Secure Session Management

Applications manage user activities with sessions. Good session management is essential for smooth interactions between the user and the application. HTTP cookies are used to maintain sessions. Improper use of cookies can cause critical web app security risks.

You can avoid security vulnerabilities with cookies by setting up flags. There are important cookie flags like SameSite, httpOnly, and Secure. Setting up the httpOnly flag can help prevent XSS attacks by eliminating potential vulnerabilities. Similarly, you can use other flags to fortify your Node application.

8. Use NodeJS Library to Prevent Injection Attacks

Injection attacks are very common these days, and attackers carry them out by injecting arbitrary queries. Attackers send queries disguised as user input to force the system to provide sensitive information. An example is an SQL injection attack in which an attacker inserts commands like “OR 1=1” in user input to fool the system into executing the command.

You can use any JavaScript library like Mongoose to ensure secure connections with the database. It will help to prevent injection attacks. It supports parameterized queries, which is an effective prevention method for SQL injection as per OWASP. Input validation and sanitization can also help check user input and remove unwanted characters.

9. Don’t Block Event Loop for Performance

The single-threaded execution model is quite flexible on its own. However, things can be difficult when CPU-intensive scripts are executed. It can cause a “blocked” situation. It occurs when a thread takes a much longer time to execute a callback or a task.

Every new or existing connection request is handled by the Event Loop in NodeJS, and it also responds to the request. However, when the Event Loop is blocked, the application will fail to process requests from any other client. The application will stuck after this.

What are the Key Node.js Security Risks?

Developing web applications with the best security features is an essential requirement. However, the complete security of your web application cannot be guaranteed when using open-source packages. Undiscovered vulnerabilities in these packages can cause various security risks for NodeJS applications. The following are the different types of Node JS web app security risks that could arise.

• Denial-of-Service: DoS attacks attempt to disrupt the normal functioning of an application by exhausting server resources. An attacker can flood your application with excessive requests to render it unresponsive. An example of this attack is Slowloris. Effective measures to prevent DoS attacks are reverse proxy, server timeouts, and limiting the number of open sockets.
• HTTP Request Smuggling: This attack occurs when a proxy is used with Node.js and there is a vulnerability in either of them. When the proxy server and Node.js interpret arbitrary requests differently, there can be potential for an attacker to launch this attack. The issue can be mitigated by configuring the proxy server to normalize arbitrary requests, using HTTP/2, and disabling the “insecureHTTPParser” option when creating the HTTP server.
• Supply Chain Attack: It refers to an attack that happens due to compromised dependencies. It can occur when the dependencies are specified carefully, or the specification is vulnerable to typosquatting. Consequently, a malicious version of the dependencies can be downloaded. Check the package.json file carefully to find any errors or typos.
• Cross-Site Scripting: XSS or Cross-Site Scripting is one of the most common attacks on Node applications. Attackers exploit applications that lack input validation to inject malicious scripts in the front end and dupe users into giving sensitive information. Proper input validation can mitigate this risk.
• Code Injection: It refers to the group of attacks in which an attacker injects malicious code into the target system and forces it to execute the code. It becomes successful due to a lack of data validation provided by users. It could be avoided if the data provided by users is checked before processing.

Find and Eliminate All Security Risks with Our Premier DAST Tool Let’s Start Now

To Wrap Up

Companies have suffered significant losses due to cybersecurity incidents over the years. Mostly, these incidents occur due to vulnerabilities like ticking bombs that can burst at any time. Therefore, a proactive approach to identifying and resolving these vulnerabilities can help you defend against these threats.

Similarly, you can protect your NodeJS applications by uncovering hidden vulnerabilities. You need an advanced Node.js vulnerability scanner like ZeroThreat to discover even hard-to-detect vulnerabilities. It can help you scan your NodeJS applications deeply and detect vulnerabilities. Try it for free to see how it works.