JavaScript Security Best Practices

JavaScript was developed in the late 1990s by Netscape. The language has gone on to become one of the most adopted and well-known programming languages in use today. JavaScript was created to add dynamic, interactive elements to a website, allowing for website developers to use more innovative and complex features and implement a better user experience.

JavaScript is now used by over 90% of websites on the world wide web, meaning most websites you visit have some form of JavaScript content on them. If the website you visit has anything other than static content, such as gifs and videos, then JavaScript is likely behind it. JavaScript can also be used for server-side technology.

Even though JavaScript is so widely adopted and used, some people are hesitant to adopt it because of how the language works and runs. The language has evolved to overcome these perceived faults, with TypeScript and ECMAScript allowing developers to overcome the challenge of loose typing.

Here are some of the JavaScript security best practices for 2020.

The Security of Open-Source

It’s essential that you trust the people behind your dependencies if you use third-party packages during development. JavaScript is open-source, meaning several developers trust it because the open-source nature of JavaScript means they can check the source code and verify it. With that said, there’s little to no guarantee that the source code for JavaScript – or any other open-source program – you find online is the same one downloaded as a dependency.

This is the reason that you should trust vendors and distributors of dependencies. Some companies choose to deal with no-one but the biggest and best players in the business. These people want to work with full-fledged frameworks. These frameworks provide nearly all of the functionality websites need. Popular frameworks include angular, jQuery, and React.

The downside to using an advanced framework is that sometimes people download more than they need. Users end up downloading extra data whenever they make a request to the client. Some of these packages are now being broken up into core components to help combat this. The size of jQuery has gone down drastically recently, and jQuery Core can now be downloaded separately.

Cross-Site Scripting (XSS)

Cross-site scripting, also known as XSS, is one of the more common JavaScript security problems. Cross-site scripting allows a hacker to manipulate a website and install malicious content. This content can do just about anything a hacker wants. Hackers use these scripts to deliver a malicious script to website visitors and infect their machines.

If these XSS concerns remain unresolved, they can cause all manner of problems, including account tampering, spreading malware, data loss and theft, and remote control over the browsers of visitors. There are several ways to counter XSS vulnerabilities, including validating input, sanitizing, and escaping data.

The best way to handle cross-site scripting is to stick to JavaScript security best practices. Open Web Application Security Process, also known as OWASP, is an online community delivering free tools, code, and tech to assist with security.

Always Connect to Servers Over TLS Certificates

One of the most important things you can do is use HTTPS to connect to other servers. HTTPS is better for the security of your information. This protocol creates an HTTP certificate on the server, allowing for information to pass securely between a client (your website) and the server, which process information.

The HTTP certificate creates a “handshake” between the server and client to ensure that the proper encryption keys are used to secure the data. The client encodes information using a public encryption key. The encrypted data is sent to the server. The server then uses a private decryption key to convert the encrypted data into something it can read. The private decryption key is something only the appropriate servers should have, and the encrypted data is useless without it. Even if someone intercepts the data packet, they can’t access the information within it.

Security certificates are nothing new. Most websites still use some form of SSL encryption. Unfortunately, SSL encryption isn’t the industry standard that it once was. You should look to use TLS version 1.2 at the very least.

Avoid URL Injection Problems

URL injection hacks happen when a programmer or hacker creates or injects new pages and assets on an existing website. The pages often contain specific code to send users to a different website instead. The code may also cause the business to be involved in attacks on other sites. URL injections can happen as a result of malware or software vulnerabilities, along with malicious plug-ins and unsecured directories.

The Google Search Console is one way to find these problem pages, but the best way is to check your site for errors and unexplained pages manually. Once you identify the compromised page, you can change them to protect against the vulnerability. You can also move the data source to something better suited to data transfer, such as a session or cookie. Prevent URL injection attacks by using a firewall to protect your website and using a gateway to direct traffic on the website. These measures form a protective bubble around your website to prevent injections or other similar problems.

Use CORS Headers

The header is part of the data packet used by web technologies. Every package sent to and from servers will have a header. The header describes the request and responses and may contain other information related to the specific request, including information about the user or the menu item the website should display.

Requests are made to several assets as a web page loads. This includes information such as font, audio, images, and the like. Cross-Origin resource sharing (CORS) headers are headers that you make yourself to define the sources making the information request. CORS headers also check if the request is authorized to reference those resources. CORS headers ensure that the data comes from where it claims to, such as ensuring Google fonts are sent from Google and not a third-party with malicious intentions.

These are just some of the things you can do to improve JavaScript security for your website.

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