What Is Browser Security? A Complete Guide for 2025

The web browser is the most important tool for many modern professionals. Today’s knowledge worker needs to utilize applications across internal and external networks, and the touchpoint for all of those apps and data is often their local browser.

This makes the browser a juicy attack vector for anyone trying to attack your company. After all, if everything flows through the browser, a hacker simply needs to compromise one browser extension to gain access to everything.

This is why browser security is a foundational pillar for modern security organizations. By improving browser security within your organization, you can quickly sharpen your company’s security posture and keep bad actors at bay.

What Is Browser Security?

Browser security involves protecting your organization’s web browsers, and the data that lives in them, from online threats. Since employees use browsers to access the internet, they’re a top attack vector for hackers.

Because the browser is used for so many different tasks today, the range of threats against the browser are equally broad. Attacks are typically leveled via compromised plugins.

Some of today’s top threats against browsers include:

Malware / Ransomware / Spyware
Phishing
Data exposure
Data exfiltration
Cookie Theft
Code Injection
Session Hijacking
Command-and-control attacks

Browser security refers to attempts to mitigate each of these threats and any others. For this reason, attempting to create a simple definition of browser security is complicated — just like how tricky it’d be to create a simple definition of something like “car safety”. You can write volumes about the topic, but it’s hard to create a single all-encompassing definition.

If you want to protect your company against cyberattacks, you need to secure your browsers with proper browser extension management. To do that, it’s key to understand browser security on a deep level because that impacts how you’ll ultimately decide to protect your browsers against cyberthreats.

How Browser Security Works

Due to the breadth of threats facing the modern browser, high-quality browser security is only possible when you approach the topic from many different angles.

Some security teams choose to enforce policies that push users to a single, approved browser that’s mandated for all employees. Others lock down key SaaS applications via a virtual private network (VPN) in hopes attackers don’t piggyback sessions transmitted through overseas cloud servers known as “hops”. Still others allow a variety of browsers but limit the extensions that users can install to avoid compromised plugins.

All of these are viable approaches to browser security with their own considerations. In other words, there is no one-size-fits-all approach. Browser security, like all forms of security, starts with understanding the risks to your business. You can then evaluate the tools and strategies that are available to help mitigate them.

Key Risks to Browser Security

How can browser security impact your team’s security posture?

To answer that question, you need to understand the landscape of threats all businesses face. With that in mind, let’s examine the most common browser security threats organizations need to be aware of to keep sensitive data and systems safe.

Users Downloading Risky Extensions

For reasons most often attributed to the desire for productivity, users are the biggest threat when it comes to browser security. Attempting to improve job performance, they often download browser extensions that can put your organization at risk. Further, giving users a prescribed, locked down corporate browser can be an effective way to secure their online activities and extension downloads, but it often leads to situations where users just circumnavigate it as a security control.

The main reason is because today’s knowledge workers are under tremendous performance pressure, so they are typically going to use the browsers with which they are most comfortable to enable navigation speed. Most often, however, this is also not intentional as a risky action. Users simply want to be able to perform their work with tools they like best.Compromised Extensions

Browser extensions play a crucial role in employee productivity. Extensions enable behaviors that your browser doesn’t offer by default. While extensions can make life easier for your team, they also introduce serious risks.

End users, as a rule, don’t validate the code of the extensions that they install. That means that they run the risk of installing malicious applications designed to exfiltrate information from your business and send it to attackers.

AI Extensions (Formerly “Plugins”)

It might seem premature to put a new technology like AI plugins / extensions near the top of the risk pile for browser security, but the state of AI browser security is currently dismal. As an example, this report on the Comet AI browser from competitor Brave paints a grim but common picture.

Large language model (LLM) plugins circumvent decades of browser security improvements, and exploiting them is as simple as writing a few lines of basic text. Most importantly, sending your sensitive data to an LLM as part of an extension’s ability to improve work performance is a significant data exposure risk. These LLMs are not controlled by your team, meaning there is a very high risk of compliance violations for regulated data users are working with while using the extensions, as well as intellectual property loss.

Phishing

While phishing isn’t exclusively a browser security issue, it’s one of the most effective ways to leverage a compromised browser. In this case, an attacker can compromise an extension to replace all or one part of your intended URL with malicious content, instead. For example, if you are attempting to log in to an account, it may replace the login section only with their own, spoofed version in order to capture your credentials. As with standard phishing campaigns, this enables them to sell or leverage your credentials however they choose.

Best Practices for Protecting Your Users’ Browsers

With all of these threats in view, protecting the browser is more important than ever. The reality of browser security in any era is that it’s a never-ending process that requires continuous attention. Every threat is unique, just like every extension’s versions are unique.Understand Usage Patterns

Securing browsers starts with understanding how your users interact with their browsers. That means understanding what sites they need to access for their jobs, which browsers they use most often. and the common way that data flows through your organization. You need to understand what kinds of extensions are necessary and those that are just nice to have for your users.

Most importantly, you need to understand the full risk profile of every extension before approving its installation by an end user. You also need to account for any potential productivity loss associated with blocking those extensions and might want to be prepared to offer them some alternatives that are less risky.

Develop a Risk Profile

Once you understand usage patterns, the next step is to develop a risk profile. With good information about how employees use their browsers and extensions, you can then get a better idea of your current risks. It’s also important to watch trends in the market, as the way users leverage extensions will most certainly evolve as they learn about new tools from their peers.

Identify Mitigations

Once you understand your risk profile, the next step is to identify the most efficient mitigations available. Any mitigation that you choose will come with costs. So, it’s important to align your spending with what you have to lose. If your employees have access to corporate data, connect to your corporate SaaS, and do most of their work online, it’s safe to assume that there is much to lose. This is good to keep in mind when evaluating solutions. If time has taught us anything in cybersecurity, it’s that the cost of an attack is almost always higher than the cost of security.

Roll Out Mitigations

Picking and choosing which browser security mitigations to apply is only half the battle. Rolling out these mitigations and ensuring that they’re correctly applied for all users is equally important. If you get this part wrong, even the best protections in the world won’t keep your systems safe.

Choosing and Getting Started With Browser Security Tools

As with any technology, any security tool that you choose will have its pros and cons.The goal is to find the solution that has the most pros for your context.

For instance, many security teams will choose a single, locked-down browser with a standard set of extensions and roll that out to all users. This brings a real benefit: You know exactly what platform your users are working with. But it also has a major shortcoming because it doesn’t cover other browser profiles or browser types employees may be using on the same device, which creates a security gap.

Choosing the right browser security tool means applying defense in depth principles. That means both protecting the browser employees use during their work day but also the browser they use on their phone, when they’re working from home, and even their email when they’re checking messages at a coffee shop before hopping on a plane.

The Future of Browser Security

The rise of AI-powered attacks means that the future of browser security will change faster than ever before. Gone are the days of having weeks to patch new security flaws; malicious users are rolling out exploits in hours. They can have a legitimate-looking extension uploaded to browser stores and use bots to make it look like they have millions of downloads in no time, duping even some astute end users. Further, developers of legitimate tools can be compromised, giving attackers access to compromise source code – as in the case of the Cyberhaven attack.

While that’s troubling news, it doesn’t change the best way to secure browsers — ongoing risk assessment for all extensions your users wish to download. SpinCRX offers not only this advantage, but streamlines approvals for busy IT teams.. To keep systems and data safe, your team needs to stay on top of developments in the browser security landscape all the time, and relying on manual processes is time prohibitive.

Learn more about SpinCRX, or try our Free App & Extension Risk Assessment to research the browser extensions your users are requesting.