What is an Attack Surface?
First, let’s discuss what an attack surface is before we dive into EASM.
The attack surface is basically all the ways an attacker could get into your systems. It’s at every point where someone unauthorized might be able to access or extract data from your network. This includes things like:
- Websites and web applications
- APIs
- Cloud services
- Internet-connected devices
- Employee accounts and emails
- Third-party vendors with access to your systems
Think of it as all the doors and windows to your digital network. Some are obvious, some are hidden, and some you might not even know exist. The bigger your organization, the more complex your attack surface usually is.
What Is External Attack Surface Management (EASM)?
In simple terms, it’s all about finding and monitoring every digital asset your organization has that’s visible from the outside. We’re talking websites, servers, cloud services, and even forgotten subdomains.
EASM is like taking a step back and seeing your company’s online presence through the eyes of a potential attacker. It’s a continuous process of discovering, classifying, and monitoring all these external-facing assets. The goal? To spot and fix vulnerabilities before they can be exploited.
This approach goes beyond traditional security measures. It’s not just about protecting what you know you have. It’s about uncovering the stuff you might not even realize is out there, exposed to the internet. And trust me, in big organizations, there’s often more out there than you’d think.
According to Verizon’s latest data breach report, a whopping 70% of attacks are perpetrated by external threat actors. These attackers clearly see and exploit weak points in the network perimeter that companies leave unprotected.
EASM’s comprehensive approach helps security teams maintain an up-to-date view of their organization’s attack surface, enabling them to:
- Discover shadow IT and forgotten assets
- Identify vulnerabilities and misconfigurations
- Assess and prioritize risks
- Implement necessary security measures
- Maintain compliance with security standards
Thus, by providing a holistic view of an organization’s external attack surface, EASM helps businesses proactively address security gaps and reduce their overall risk of cyber attacks.
Different Between Internal vs External Attack Surface Management
Internal Attack Surface Management
This is all about what’s going on inside your network. It’s the stuff behind your firewall, the systems and data that (in theory) only your employees and authorized users can access. Here’s what it typically covers:
- Internal networks and servers
- Employee workstations and devices
- On-premises applications
- Data storage systems
- User accounts and permissions
The goal here is to lock down your internal systems, making sure there are no weak spots that an attacker could exploit if they managed to get inside your network. It’s about things like:
- Making sure all your internal systems are patched and up-to-date
- Monitoring user behavior for anything suspicious
- Controlling access to sensitive data
- Securing internal communications
External Attack Surface Management
This is what we’ve been talking about—it’s all about your public-facing assets. Anything that’s connected to the internet and could potentially be accessed by someone outside your organization. This includes:
- Websites and web applications
- Public-facing APIs
- Cloud services
- Internet-connected devices
- Email servers
- Anything else that’s visible from the outside
EASM is focused on finding and securing all these external touchpoints. It’s about discovering assets you might not even know you have, and making sure they’re not leaving you open to attack.
Key Differences
Scope: Internal is about what’s inside your walls, External is about what’s facing the outside world.
Visibility: Internal assets are (usually) easier to track because you control them directly. External assets can be trickier – they might be spread across different cloud services or managed by different departments.
Access: Internal management deals with authorized users and how they interact with your systems. External management is more about preventing unauthorized access in the first place.
Tools: While there’s some overlap, the tools and techniques for managing internal and external attack surfaces can be quite different.
Why You Need Both
Here’s the thing—you can’t just focus on one or the other. A solid security strategy needs both. Attacks often involve multiple stages. An attacker might use a vulnerability in your external attack surface to gain a foothold, then exploit weaknesses in your internal systems to move around and access sensitive data.
Hence, by managing both your internal and external attack surfaces, you’re creating a more comprehensive defense. It’s about securing your perimeter and your core, giving attackers fewer opportunities to cause harm.
Why is EASM Crucial?
Visibility into Unknown Assets
You can’t protect what you don’t know about. That’s the core problem EASM solves. As companies grow, merge, or adapt to new technologies, they often lose track of some of their digital assets. Maybe it’s an old server someone forgot to decommission, or a dev environment that accidentally went live. EASM helps you find these forgotten or unknown assets before attackers do.
Continuous Monitoring in a Dynamic Environment
The internet doesn’t stand still, and neither does your attack surface. New vulnerabilities pop up daily, and your digital footprint is constantly changing. EASM provides ongoing monitoring, alerting you to new risks as they appear. This real-time insight is crucial in a world where a single unpatched vulnerability can lead to a major breach.
Prioritizing Security Efforts
Let’s face it, most security teams are stretched thin. They need to focus their efforts where it matters most. EASM helps by identifying your most critical and exposed assets, allowing you to prioritize your security efforts and resources more effectively.
Third-Party Risk Management
Your security is only as strong as your weakest link, and often that link is a third-party vendor or partner. EASM can help you understand the risks associated with your external connections, giving you a clearer picture of your overall security posture.
Compliance and Risk Management
Many industries have strict rules about data protection and cybersecurity. EASM gives you the visibility you need to prove you’re meeting these standards. It can also help you spot compliance issues before they become problems during an audit.
Improves Incident Response
When something does go wrong, EASM gives you a head start. You’ll have a clear map of your entire attack surface, making it easier to trace how an attacker got in and what they might have accessed. This can dramatically speed up your response time and limit the damage.
Reducing the Window of Opportunity for Attackers
Since it can continuously scan for and address vulnerabilities, EASM significantly reduces the time that weaknesses are exposed. This narrows the window of opportunity for attackers, making it much harder for them to find and exploit vulnerabilities in your systems.
How Does EASM Work?
Continuous Discovery
EASM tools are always on the hunt. They scan the Internet, looking for anything connected to your organization. This includes obvious stuff like your main website but also things you might have forgotten about—old subdomains, cloud assets, or even shadow IT projects some department spun up without telling anyone.
Asset Inventory
As the tool finds things, it builds a detailed list. This isn’t just a simple catalog. It logs information about each asset – what it is, what it does, what software it’s running, and how it’s configured. It’s like a constantly updated map of your digital world.
Risk Assessment
Now comes the detective work. The EASM system analyzes each asset for potential vulnerabilities. It’s looking for outdated software, misconfigurations, weak encryption—anything an attacker might exploit. It also considers how critical each asset is to your business.
Prioritization
Not all risks are created equal. EASM tools use fancy algorithms to rank the issues they find. They consider stuff like how easy a vulnerability is to exploit, how much damage it could cause, and how valuable the target is. This helps your security team focus on the most urgent problems first.
Monitoring and Alerts
This isn’t a set-it-and-forget-it deal. EASM keeps watching your attack surface 24/7. If it spots a new vulnerability or a change that could create a security risk, it alerts your team right away. Some systems can even automatically trigger defensive measures.
Integration
EASM doesn’t work in isolation. Good systems play nice with your other security tools. They might feed data into your SIEM (Security Information and Event Management) system or your vulnerability management platform. This gives your security team a more complete picture of your overall security posture.
Reporting and Visualization
Raw data is hard to act on. EASM tools turn all that information into easy-to-understand reports and dashboards. These show trends over time, highlight critical issues, and give you a bird’s-eye view of your attack surface. It’s great for both daily operations and when you need to explain security to the higher-ups.
Continuous Improvement
As your organization changes, so does your attack surface. EASM adapts to these changes, continuously refining its understanding of your digital footprint. It learns from past scans, becoming more accurate and efficient over time.
Conclusion
Every exposed asset is a potential entry point for a cyberattack, putting your data, reputation, and even financial stability at risk. Hackers are constantly searching for weaknesses, and with the ever-expanding digital landscape, even a single exposed asset can be your downfall. Legacy security measures just can’t keep up.
EASM is your chance to take control, identify those hidden vulnerabilities, and eliminate them before attackers do. It’s the proactive defense you need in today’s relentless threat landscape. Don’t wait for a breach to be your wake-up call. Take action today and secure your organization’s digital perimeter with EASM.
