Understanding Attack Surfaces in Cybersecurity

In cybersecurity, the attack surface refers to all the points where a cybercriminal could gain access to a firm’s systems or data. It includes everything from exposed servers and cloud apps to employee endpoints and weak passwords. 

As businesses adopt remote work, cloud platforms and third-party tools, these attack surfaces are expanding fast – and often in ways they can’t fully track. However, without full visibility and control into every network touchpoint, these growing digital footprints create serious risk. 

Therefore, understanding and managing your attack surface is now a critical part of staying secure in today’s complex threat landscape.

Every organization has multiple attack surfaces. Each one represents a different opportunity for threat actors to gain access, disrupt operations, or steal data. Understanding the key types is the first step in identifying where your greatest risks lie. There are three basic attack surfaces firms must be familiar with.

This includes all internet-facing assets that connect your network to the outside world. Websites, cloud services, SaaS platforms, exposed ports, public APIs and forgotten subdomains all come under this category.

Common vulnerabilities on these surfaces include misconfigured cloud storage, unpatched web apps, outdated software and unsecured APIs, which can all be exploited by hackers. For example, in 2023, the MOVEit breach exploited a file transfer tool vulnerability, leaving thousands of firms exposed.

This category refers to hardware and on-site infrastructure including desktops, laptops, mobile devices, servers, USB ports and IoT devices. Stolen or lost devices can expose sensitive data to criminals, while these endpoints can also be used by hackers to exfiltrate data as part of a double extortion ransomware attack.

The human element is another key attack surface that must be factored into a cybersecurity strategy. Employees, contractors, suppliers and partners can all be targeted by criminals to gain entry to a network.

Common ways these can be exploited include phishing emails, poor password practices that make brute fore attacks easier, social engineering and accidental data sharing. The MGM Resorts breach in 2023, for example, was triggered by voice phishing, demonstrating how attackers exploit people to infiltrate networks.

Modern business environments are becoming increasingly complex as firms expand and encounter network sprawl, while new working practices are also leading to a significant expansion of attack surfaces. Several key factors contribute to this growth, including the following.

• Shadow IT: Employees often adopt unauthorized tools and applications without IT approval, increasing security risks. It’s estimated that by 2027, three-quarters of employees (75 percent) will acquire, modify or create technology outside IT’s visibility.
• Remote and hybrid work: The shift to flexible working has introduced new vulnerabilities as users connect using unsecured networks and on personal devices. In the UK, for example, more than a quarter of people have hybrid working arrangements as of 2024.
• Cloud computing: The adoption of cloud services has outpaced the implementation of adequate security controls. According to Cybersecurity Insiders, for example, 61 percent of organizations reported cloud security incidents in 2024, with more than one in five firms reporting data security issues on these platforms.
• Connected devices: The number of connected Internet of Things (IoT) devices is also rapidly increasing, with these items projected to have reached 18.8 billion globally by the end of 2024. This greatly increases the number of potential access and data exfiltration points for hackers to take advantage of.

These trends underscore the importance of comprehensive attack surface management to mitigate the growing risks associated with an expanding digital footprint.

When organizations don’t have full visibility of their attack surface, they leave critical entry points exposed to hackers and other unauthorized individuals. Unsecured endpoints, forgotten cloud assets, or employee-owned devices can all act as hidden backdoors. What’s more, many of these will go undetected by security teams until it’s too late.

Some of the most serious consequences of this include:

• Data breaches from exposed credentials or misconfigured systems.
• Ransomware attacks exploiting unpatched software.
• Compliance and privacy violations due to overlooked assets storing sensitive data.
• Prolonged dwell time, allowing attackers to move laterally within systems while remaining undetected.

As digital environments grow more complex, organizations need more than firewalls and endpoint security. They must have continuous visibility across their entire environment. Attack Surface Management (ASM) is the proactive process of identifying, monitoring and reducing all potential entry points across the entire infrastructure, from cloud environments and endpoints to third-party tools and user behaviors.

Effective ASM starts with asset discovery, but it goes further. Important strategies include real-time scanning, risk analysis and the ability to respond quickly to new exposures and vulnerabilities. Key tools and technologies include:

• External Attack Surface Management (EASM) platforms that map publicly exposed assets and identify weak points.
• Endpoint Detection and Response (EDR) tools that monitor device behavior and flag suspicious activity.
• Cloud Security Posture Management (CSPM) solutions for spotting and remediating misconfigurations across cloud infrastructure.
• Anti Data Exfiltration (ADX) technology, which acts as a last line of defense by blocking unauthorized data transfers, even when attackers breach perimeter security.

These tools work best when integrated into a unified threat prevention strategy that emphasizes visibility, automation and rapid response.

Reducing your attack surface for all types of cybercrime isn’t about eliminating risk entirely. It’s about making your environment harder to compromise and easier to monitor. Here are seven essential steps every organization should take to achieve this:

1. Conduct regular asset discovery to identify unknown or shadow IT systems.
2. Apply least-privilege access and role-based permissions to limit exposure.
3. Patch vulnerabilities quickly across all systems and applications.
4. Segment networks to isolate critical systems and contain threats.
5. Use encryption to secure data at rest and in transit.
6. Deploy endpoint and ADX protection to detect and block data exfiltration.
7. Train employees to recognize phishing and social engineering attempts.

Consistent execution of these practices significantly reduces the risk of attack and helps ensure fast, effective response if one occurs.