Attack Surface

What is an Attack Surface?

An organization’s attack surface is all the ways a hacker can break in.

Think of it like a house, every door, window, and vent is a potential entry point.

In cybersecurity, these “entry points” are vulnerabilities in your software, network, and even employees.

The goal? Shrink this surface as much as possible.

The smaller the attack surface, the fewer opportunities there are for an attacker to exploit.

Here’s a breakdown of the different types of attack surfaces:

Four types of attack surfaces

1. Digital Attack Surface: This includes all network connections, ports, protocols, and devices connected. It also includes all the vulnerabilities in the various applications and servers. Cloud services and cloud infrastructure can extend the attack surface as well.
2. Physical Attack Surface: Physical devices and their individual components. As well as physical access to buildings or rooms where sensitive data is stored.
3. Human Attack Surface: Manipulating people into sharing confidential information. Disgruntled employees and contractors who have access to sensitive data can become insider threats.
4. Operational Attack Surface: Vulnerabilities in operational workflows and processes. For example, weak password policies, poor employee training, and weak incident response plans.

Attack Surface vs. Attack Vectors: What’s the Difference?

Your attack surface is the *what*. It’s the sum of your system’s entry points and vulnerabilities.

Attack vectors are the how. They’re the specific techniques (phishing, malware, etc.) used to exploit those openings.

Defining your attack surface

Mapping your attack surface is like drawing a detailed floor plan of a building. Here’s how to get started:

1. Asset Inventory: List all physical devices, like servers, desktops, laptops, and mobile devices. Also, catalog all software applications and their versions. This includes operating systems, third-party applications, in-house developed software, and cloud services. Finally, identify all of the places where sensitive data is stored, processed, or transmitted. This includes databases, file storage, and code repositories.
2. Network Mapping: Document all internal networks, including IP address ranges and netmasks. List all public-facing (NATted) IPs, domain names, and subdomains. Finally, map all connections between devices and networks. This includes VPNs, Wi-Fi networks, and remote access points.
3. Entry Points Identification: Identify all open ports and running services on each device. Map which services are internal or external. Include specific software versions and patch levels. List all of your web applications, APIs, and other endpoints. Include email servers, gateways, and other related services.
4. User Access Review: List all user accounts, including employees, contractors, and third-party partners. Document access permissions for each type of account (basic user, admin, etc.). Document which authentication methods are used, such as passwords, MFA, and SSO.
5. Third-Party Integrations: List all third-party services, applications, and vendors integrated with your systems. Document all API connections and software dependencies on external services.
6. Physical Security Assessment: List all the places where IT assets are located. This includes offices, data centers, and remote sites. Review the security defenses in place. Consider requiring keycards or biometrics to gain access.
7. Process and Procedure Analysis: Document all critical business processes. This includes things like how developers deploy code and backup schedules. Include security policies related to patch management, backups, and employee training.
8. Continuous Monitoring and Updates: Regularly scan for vulnerabilities. External consultants should perform penetration tests periodically. Run security audits to identify new vulnerabilities. Passively monitor for shadow IT to ensure all servers are properly locked down. Monitor the dark web for leaked login credentials and company data. Early detection helps prevent unauthorized access.

Reducing your attack surface in five steps

1. Inventory Everything: List all digital assets. Include hardware, software, network devices, and data repositories. Identify potential vulnerabilities for each asset to understand where the highest risks are.
2. Tighten Access: Restrict access to critical systems and data to authorized users only. Enforce the use of strong, unique passwords via a password manager. Implement multi-factor authentication (MFA) to add an extra layer of security.
3. Patch and Update: Keep all software and systems up-to-date with the latest patches. Schedule regular maintenance windows to ensure vulnerabilities are quickly addressed.
4. Monitor Proactively: Continuously monitor network traffic for signs of attack. Monitor the dark web for leaked credentials or company data. Track potential phishing domains and newly registered domains that are similar to yours. Configure automated alerts when anomalies are found.
5. Train Your Team: Educate employees on security best practices. Stress the need to protect sensitive information. Train staff regularly to help them avoid common mistakes, like phishing attacks.