Defining Your Organization's Attack Surface: The 4 Types of Attack Surfaces

Attack surfaces are a fundamental concept within information security. However, attack surfaces can be constituted of different things. For example, some formulations of an attack surface include not just software and hardware, but the people using them. In this post, we’re going to cover four common types of attack surface, discuss how you should think about the risks associated with each type, and best practices for addressing these risks.

What is an attack surface?

Attack surfaces effectively describe the vulnerabilities that emerge from the relationships between all of the hardware, software, network components, user interfaces, and human factors within your environments that can be targeted to gain unauthorized access to sensitive information or disrupt critical systems. The larger and more complex the attack surface, the higher the risk of a successful cyberattack, unless the attack surface is actively monitored or managed.

Why attack surfaces matter

Understanding and managing attack surfaces is crucial for organizations to maintain a strong security posture. A smaller and well-protected attack surface reduces the likelihood of a successful cyberattack, thereby minimizing the potential damage to the organization's reputation, finances, and operations. As businesses increasingly rely on digital technologies, their attack surfaces expand, making it essential to identify, assess, and address potential risks proactively.

What are the different types of attack surfaces?

As technology has grown in complexity, the ways to think about and categorize attack surfaces have grown. At a high level, though, the OSI model provides a useful analogy for thinking about where attack surfaces can exist and how to protect them. Below, we’ll discuss the different broad categories of attack surfaces and the types of risks associated with each.

1. Cloud attack surface

While a cloud attack surface can include many of the contents discussed above, because cloud systems tend to be perimeter-less, many organizations struggle with managing this type of attack surface. This is because unlike corporate intranets and networks, it’s often not possible to deploy controls like firewalls, traditional access controls, and other tools that “contain” or confine cloud data and cloud system access to one area of the cloud. Perimeter-less systems by definition tend to be open in order to allow for the rapid exchange of information across large and distributed teams.

We’ve talked before about cloud attack surfaces at length, see the video below for a visual representation of how to think about how the attributes of cloud systems contribute to the growth of cloud attack surfaces.

2. Network attack surface

This involves the communication channels between devices, systems, and users. Risks include unsecured network protocols, weak encryption, and poorly configured firewalls, which can be exploited to intercept, manipulate, or disrupt data flows.

3. Software attack surface

This consists of applications, operating systems, and firmware that run on devices. Vulnerabilities in the code, misconfigurations, or outdated software can be exploited by attackers to gain unauthorized access or compromise systems.

Application attack surface

Software applications, especially web applications, are a complex mesh of components like code, APIs, databases, and might incorporate different microservices or other smaller program-like components that themselves must be secured.

Web attack surface

The concept of a web attack surface refers to vulnerabilities in web assets and services that can be used to take down a website or use a web server as a launchpad for a deeper intrusion into an organization's systems.

4. Physical attack surface 

Physical attack surfaces are those that exist when an attacker has access to a physical location containing machines with sensitive systems or information, or devices that can connect to such machines. Some examples of physical attack surfaces can include:

Hardware & endpoint attack surface

This includes physical devices such as servers, workstations, routers, switches, and IoT devices that can be exploited by attackers. Risks include unauthorized access, tampering, theft, and hardware-based vulnerabilities.

IoT attack surface

Internet of Things (IoT) systems can include “always-on” low level processors that can execute malicious code when hijacked. Although many IoT exploits tend to be remote, it’s worth taking into consideration what systems and devices an IoT product or service is connected to locally.

Protection Strategies for Attack Surfaces

Understanding and managing your organization's attack surface is a vital part of a robust cybersecurity strategy. By taking proactive measures to identify potential vulnerabilities, reduce attack vectors, and educate employees on the risks, you can significantly decrease the likelihood of a successful cyberattack and protect your organization's valuable assets. Some of the following practices are important for doing this.

1. Asset Management and Monitoring

• Asset Inventories: Maintain a comprehensive inventory of all hardware, software, and network components. This includes documenting their configuration, purpose, and location, which helps identify potential vulnerabilities and prioritize security efforts.
• Vulnerability Scanning: Regularly scan your systems for known vulnerabilities using automated tools, and promptly apply patches or updates to address any detected issues. Regular vulnerability assessments can help prevent attackers from exploiting outdated software or misconfigurations.
• Preventing Shadow IT: Monitor and control the use of unauthorized software, hardware, or cloud services within the organization. Educate employees on the risks of shadow IT, and implement robust processes for the approval and deployment of new technologies.
• Scanning for Inappropriate Data Sharing: Regularly audit data access and sharing policies to identify instances of sensitive information being shared inappropriately. Implement data loss prevention (DLP) tools to monitor, control, and prevent unauthorized data transfers.

2. Access Control and Authentication

• Managing Account Permissions: Limit user privileges by implementing the principle of least privilege, ensuring that users have only the necessary access required to perform their jobs. Regularly review and update user permissions to minimize the risk of unauthorized access or privilege escalation.
• Implementing Multi-Factor Authentication (MFA): Strengthen access control by requiring multiple forms of verification, such as a password, a security token, or biometric data, before granting access to sensitive systems or information.

3. Network and system security

• Network Segmentation: Divide your network into smaller segments, isolating critical systems and data from less secure areas. This approach can help contain a potential breach and limit the attacker's ability to move laterally within your network.
• Intrusion Detection and Prevention Systems (IDPS): Deploy IDPS solutions to monitor network traffic for malicious activities and potential threats. These tools can identify and block known attack patterns, helping to protect your attack surface from intruders.
• Regular Security Audits and Penetration Testing: Conduct periodic security audits to assess your organization's security posture and identify potential weaknesses. Engage external penetration testers to simulate real-world attacks and validate the effectiveness of your defenses.
• Security Incident and Event Management (SIEM): Implement a SIEM solution to collect, analyze, and correlate security events from various sources. This can help in detecting and responding to security incidents more efficiently, minimizing the potential impact of a breach.

4. Human-Centric Strategies

• Regular Security Training and Awareness Programs: Educate employees on cybersecurity best practices, common threats, and how to identify and report suspicious activities. A well-informed workforce can act as the first line of defense against cyber threats.
• Secure Development Lifecycle (SDLC): Integrate security best practices into your software development process. This includes conducting regular code reviews, using static and dynamic analysis tools, and addressing vulnerabilities before deploying applications.

Conclusion

Ultimately with good security practices in place for both security admins as well as employees and end users, attack surface management doesn’t have to be difficult. To consider related risks across remote workforces, read our Security Playbook for Remote-first Organizations.