Attack Surface


What is an Attack Surface?

An attack surface refers to all the different points where an unauthorized user (like a hacker) can try to enter or extract data from your system.

Think of it like a house: the attack surface includes all the doors, windows, and other openings through which someone could potentially break in.

In the context of cybersecurity, these “openings” can be anything from software vulnerabilities, network connections, user accounts, to physical access points.

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

Four types of Attack Surface

There are four major types of attack surfaces which can be further broken down into smaller components. These include:

1. Digital Attack Surface:

  • Network Attack Surface: Includes all network connections, ports, protocols, and devices connected to the network. Examples: open ports, unpatched network devices.
  • Software Attack Surface: Consists of vulnerabilities in applications and operating systems. Examples: bugs, outdated software, insecure APIs.
  • Web Attack Surface: Encompasses web applications and servers. Examples: SQL injection, cross-site scripting (XSS), unprotected endpoints.
  • Cloud Attack Surface: Involves vulnerabilities in cloud services and infrastructure. Examples: misconfigured cloud storage, insecure APIs, improper access controls.

2. Physical Attack Surface:

  • Hardware Attack Surface: Includes physical devices and components. Examples: tampered hardware, USB drives, IoT devices.
  • Facility Attack Surface: Refers to physical access to buildings and rooms where sensitive data is stored. Examples: unlocked doors, lack of surveillance.

3. Human Attack Surface:

  • Social Engineering Attack Surface: Involves manipulating people into divulging confidential information. Examples: phishing emails, pretexting, baiting.
  • Insider Threat Attack Surface: Concerns employees or contractors who have access to the system. Examples: disgruntled employees, compromised credentials.

4. Operational Attack Surface:

  • Processes and Procedures: Includes vulnerabilities in operational workflows and protocols. Examples: weak password policies, inadequate employee training, insufficient incident response plans.

Attack vectors and attack surfaces are closely related concepts in cybersecurity:

  • Attack Surface: Refers to all the possible points (or “surface area”) where an attacker can try to enter a system or extract data. It’s essentially the total sum of vulnerabilities or entry points in a system.
  • Attack Vectors: These are the specific methods or paths that attackers use to exploit the vulnerabilities in the attack surface. An attack vector could be a phishing email, a malware infection, a brute force login attempt, or a SQL injection attack, among others.

In simple terms, the attack surface is like a map showing all the doors and windows (vulnerabilities) of a building (system), and attack vectors are the tools or techniques (methods) threat actors use to break in through those points.

By reducing the attack surface, you limit the number of entry points an attacker can exploit. Monitoring and defending against attack vectors helps to protect those entry points from being successfully breached.

How To Define Your Attack Surface Area

Creating a detailed map of your attack surface area enables you to better understand your risk as well as prioritize mitigation efforts. Here’s a comprehensive guide to help you define your attack surface area:

1. Asset Inventory:

  • Hardware: List all physical devices, including servers, desktops, laptops, mobile devices, and network hardware (routers, switches, firewalls, etc.).
  • Software: Catalog all software applications, including operating systems, third-party applications, in-house developed software, and cloud services.
  • Data: Identify where sensitive data is stored, processed, and transmitted, including databases, file storage, and data repositories.

2. Network Mapping:

  • Internal Network: Document all network segments, internal IP addresses, and subnetworks.
  • External Network: List all public-facing IP addresses, domain names, and external network interfaces.
  • Connections: Map all connections between devices and networks, including VPNs, Wi-Fi networks, and remote access points.

3. Entry Points Identification:

  • Open Ports and Services: Identify all open ports and running services on each device, both internal and external.
  • Web Applications and APIs: List all web applications, APIs, and endpoints accessible from the internet.
  • Email Systems: Include email servers, gateways, and related services.

4. User Access Review:

  • User Accounts: Catalog all user accounts, including employees, contractors, and third-party partners.
  • Access Levels: Document access permissions and roles for each account, focusing on privileged accounts.
  • Authentication Methods: Review authentication mechanisms in place, such as passwords, multi-factor authentication (MFA), and single sign-on (SSO).

5. Third-Party Integrations:

  • Vendors and Partners: List all third-party services, applications, and vendors integrated with your systems.
  • APIs and External Services: Document all API connections and dependencies on external services.

6. Physical Security Assessment:

  • Facilities: Identify all physical locations where IT assets are located, including offices, data centers, and remote sites.
  • Physical Access Controls: Review measures in place to control physical access, such as keycards, biometrics, and surveillance systems.

7. Process and Procedure Analysis:

  • Operational Workflows: Document critical business processes and procedures, such as software development, deployment, and incident response.
  • Policies: Include security policies related to patch management, backups, and employee training.

8. Continuous Monitoring and Updates:

  • Regular Assessments: Perform regular vulnerability scans, penetration tests, and security audits to identify new vulnerabilities.
  • Change Management: Passively monitor your asset inventory and update your network diagrams regularly to reflect changes in your environment, such as new assets, software updates, and network reconfigurations.
  • Dark Web Monitoring: Continuously monitor the dark web for leaked login credentials, session tokens, or leaked company data that could be used to gain unauthorized access.

Reduce Your Attack Surface in Five Steps

Attack surface management helps security teams gain visibility into all potential entry points and vulnerabilities. The reduce your attack surface, consider the following steps:

  1. Inventory and Assess: Create a list of all digital assets, including hardware, software, network devices, and data repositories. Identify potential vulnerabilities for each asset to understand where the highest risks are.
  2. Implement Strong Access Controls: Restrict access to critical systems and data to authorized users only. Enforce the use of strong, unique passwords and implement multi-factor authentication (MFA) to add an extra layer of security.
  3. Patch and Update Regularly: Keep all software and systems up-to-date with the latest security patches and updates. Schedule regular maintenance windows to ensure vulnerabilities are quickly addressed.
  4. Monitor and Respond: Continuously monitor network traffic as well as the dark web for signs of attack. Set up alerts for network anomalies, leaked credentials, potential phishing domains registered, or new digital assets found.
  5. Educate and Train: Educate employees on security best practices and the importance of protecting sensitive information. Conduct regular training sessions to ensure staff know how to avoid common pitfalls, such as phishing attacks.