Attack Surface Management: Process, Components & Practices

What Is Attack Surface Management (ASM)? 

Attack surface management (ASM) is the process of identifying and managing potential vulnerabilities in an organization’s IT infrastructure, applications, and systems. The attack surface is the sum of all the different points or entryways through which an attacker can enter the system or exploit a vulnerability.

ASM involves identifying and assessing these entry points and vulnerabilities, and then implementing measures to minimize or eliminate them. This includes both external-facing assets such as web applications, network devices, and servers, as well as internal assets such as endpoints and databases.

The goal of ASM is to reduce an organization’s attack surface, making it more difficult for attackers to gain access to sensitive data, compromise systems, or launch cyberattacks. ASM is a critical component of an organization’s overall cybersecurity strategy and helps to ensure that security risks are effectively managed and mitigated.

This is part of a series of articles about vulnerability management

In this article:

• How Does Attack Surface Management Work?
• Key Components of an Attack Surface Management Program
• Classification, Prioritization, and Security Ratings
• How to Implement Attack Surface Management Programs

How Does Attack Surface Management Work? 

ASM is a continuous process that includes the following five steps:

1. Discover Assets

ASM requires identifying and cataloging all the assets in an organization’s IT infrastructure. This involves conducting a comprehensive inventory of all assets, including servers, workstations, network devices, web applications, databases, and other components. 

Asset discovery can be done manually, but many organizations use automated tools to help speed up the process. Automated asset discovery tools use techniques such as network scanning, port scanning, and fingerprinting to identify all assets within the organization’s network.

2. Test Continuously

Once all assets are identified, the next step is to continuously test and monitor them for vulnerabilities and other security risks. This involves using a combination of automated and manual testing techniques, such as: 

• Vulnerability scanning tools: Automatically identify and test for known vulnerabilities in applications and systems. 
• Penetration testing: Involves simulating an attack on the organization’s systems to identify potential vulnerabilities. 
• Code review: Involves reviewing the source code of applications to identify potential security flaws.

3. Get Context

After identifying and testing the assets, the next step is to gather context about the risks associated with each asset. This includes understanding the asset’s role in the organization, its criticality, and the potential impact of a security breach. This information can be obtained by consulting with the asset owners and business stakeholders, as well as by reviewing the organization’s risk management policies and procedures.

4. Prioritize

The next step is to use the context data to prioritize the assets based on their level of risk. This involves ranking the assets according to the severity of the vulnerabilities and the potential impact of a security breach. Prioritization helps ensure that the organization’s limited resources are directed toward addressing the most critical risks first.

5. Remediate

The final step is to remediate the vulnerabilities and security risks identified during the testing and prioritization phases. This may involve implementing software patches, updating configurations, or modifying application code. Remediation should be done in a timely and coordinated manner, with clear communication to all stakeholders.

Key Components of an Attack Surface Management Program 

Here are four key components of a comprehensive cyber attack surface management program:

Classification, Prioritization, and Security Ratings

This component involves identifying and classifying assets based on their criticality to the organization’s operations, the sensitivity of the data they handle, and the potential impact of a security breach. Once assets are classified, they can be prioritized based on their risk level, allowing the organization to focus its resources on the most critical assets.

Based on the assigned priorities, an ASM program assigns a security rating to each asset, taking into account factors such as known vulnerabilities, configuration issues, and patching levels. Security ratings help organizations to prioritize remediation efforts and allocate resources to address the most critical risks.

Network Segmentation

Network segmentation involves dividing an organization’s IT infrastructure into smaller, more manageable segments, each with its own set of security controls. By implementing network segmentation, organizations can limit the attack surface and prevent lateral movement by attackers within the network. Network segmentation can also improve visibility into network traffic and allow for more targeted threat detection and response.

Security Threat Intelligence

This component involves monitoring external sources for information about emerging threats, vulnerabilities, and attack techniques. This information can be used to inform ASM efforts and to proactively identify and mitigate potential risks. Security threat intelligence can be obtained from a variety of sources, including commercial threat intelligence providers, open-source intelligence, and information sharing forums.

How to Implement Attack Surface Management Programs

Assess the ASM Platform and Its Features

Here are some factors to consider when assessing the ASM platform and its features:

• Functionality and scalability: The tool can identify all assets within an organization’s IT infrastructure, test for vulnerabilities, and provide reports and analytics. It can also scale to meet the needs of the organization as it grows and expands. 
• Ease of use and customizability: It should have a clear and intuitive interface that makes it easy for security teams to identify vulnerabilities and track remediation efforts. Additionally, it should allow organizations to customize workflows, dashboards, and reports.
• Integration: It must integrate with other security tools and technologies, such as security information and event management (SIEM), identity and access management (IAM), and network access control (NAC) solutions. Integration with other tools can help to improve visibility into security risks and facilitate threat detection and response.

Put Policies and Training in Place after ASM Is Introduced

Once an ASM tool is in place, organizations should establish policies and procedures to guide its use. This may include defining roles and responsibilities for team members, establishing workflows for vulnerability remediation, and setting criteria for asset classification and prioritization. In addition, organizations should provide training to employees on the use of the ASM tool and the importance of ASM in managing cybersecurity risks.

Measure ASM Platform and Program Success

To ensure the effectiveness of the ASM tool and the overall program, it is important to measure its success over time. This may involve tracking key performance indicators (KPIs), such as the number of assets discovered, the number of vulnerabilities identified and remediated, and the overall reduction in the attack surface. Organizations can also measure the success of the program by conducting periodic assessments, such as penetration testing and red team exercises.