What is Attack Surface Management ?

Attack Surface Management (ASM) is the process of monitoring, managing and reducing an organization’s attack surface, which comprises all the vulnerabilities and weaknesses that malicious actors can exploit to gain unauthorized access. ASM helps identify, monitor, and minimize an organization’s attack surface by gaining visibility into IT assets, vulnerabilities, and cyber risks.

Attack Surface Management Solutions use asset discovery and inventory tools to gain visibility into all IT assets, including virtual, cloud, and shadow IT infrastructure and other previously unknown assets. They scan these assets for vulnerabilities and software misconfigurations that could be exploited. ASM also monitors an organization’s external digital footprint, like domains and subdomains, to identify risks from exposed assets.

Armed with this information, cybersecurity teams can prioritize and mitigate the highest risks across the organization’s attack surface. They can also simulate real-world cyberattacks to identify blind spots and see how well their defenses hold up. By shrinking the attack surface, organizations reduce the opportunities for compromise and make it more difficult for attackers to gain a foothold.

Understanding the Attack Surface

An organization’s attack surface refers to all the possible entry points that could be exploited by an attacker to compromise systems and data. This includes on-premises assets like servers, desktops, routers and IoT devices, as well as identity and access management systems, cloud assets, and external systems connected to the organization’s network.

The attack surface is constantly evolving as new digital infrastructure, devices, and connections are added over time. New vulnerabilities are frequently discovered in software and systems, and attackers are constantly developing new exploitation techniques. This means the attack surface is continually expanding and introducing new risks.

Some of the most common entry points in an attack surface include:

  • On-premises endpoints like servers, desktops, laptops and IoT devices. These contain valuable data and access, and are often targeted.
  • Cloud assets such as storage, databases, containers, and serverless functions. Cloud adoption has greatly increased the attack surface for most organizations.
  • Identity and access management systems. Identity is an attack surface, since compromised credentials are one of the top attack vectors used to breach networks.
  • External connections to partners, customers or subsidiary networks. These connections expand the attack surface and introduce risks from less trusted networks.
  • Shadow IT systems set up by employees without organizational approval or oversight. These hidden systems are security blind spots in the attack surface.

Attack surface management is the practice of continuously identifying, analyzing, and reducing potential entry points to minimize risks. This includes gaining visibility into all assets, connections and access points in the organization’s infrastructure, and taking action to shrink the attack surface by closing vulnerabilities, reducing excess access, and improving security controls.

The Value of Attack Surface Management

Attack Surface Management (ASM) provides significant value to organizations in managing cyber risk. ASM tools automatically discover and map all assets across an organization’s environment, identifying vulnerabilities and misconfigurations. This enables security teams to gain visibility into the scope of their attack surface, prioritize risks, and remediate issues.

Improved Security Posture

By gaining a comprehensive understanding of all assets and vulnerabilities, ASM strengthens an organization’s security posture. Security teams can identify weaknesses, close security gaps, and reduce opportunities for compromise. With continuous monitoring, ASM solutions provide an always-up-to-date inventory of assets and risks. This allows organizations to make risk-based decisions and focus resources on the highest priority items.

Reduced Risk

ASM mitigates risk by patching vulnerabilities and misconfigurations that could be exploited in an attack. Solutions can automatically discover new assets as they come online, check for vulnerabilities, and notify security teams so they can remediate risks before they are targeted. ASM also allows organizations to model how changes might impact their attack surface, so they can make adjustments to avoid increasing risk. By shrinking the attack surface, ASM makes it more difficult for adversaries to find entry points into the environment.

Improved Compliance

For organizations with regulatory compliance requirements, ASM provides documentation and reporting to demonstrate risk management practices. Solutions track assets, vulnerabilities, and remediation in an auditable format. This reporting can help organizations comply with standards like PCI DSS, HIPAA, and GDPR. ASM gives an overview of the current security posture at any point in time and a historical record of risk and remediation.

Core Functions of Attack Surface Management

Attack Surface Management (ASM) involves several core functions to help organizations identify, monitor, and reduce their attack surface.


The discovery phase focuses on identifying an organization’s digital assets, including hardware, software, and services. This involves scanning networks to find connected devices and cataloging details about the operating systems, applications, and services running on them. The discovery process aims to create an inventory of all assets that could be potential targets for cyber attacks.


Penetration testing and vulnerability assessments are used to identify weaknesses in an organization’s IT infrastructure and software. Ethical hackers will attempt to compromise systems and gain access to data to determine how attackers could exploit vulnerabilities. The testing process highlights risks that need to be addressed to strengthen security.


The context function examines how identified assets relate to business operations and assesses their importance. Critical data, systems, and infrastructure are prioritized to help determine where resources should be focused. Context also considers how vulnerabilities could be chained together for maximum impact. This helps organizations understand how exposed their critical assets are and the potential consequences of a cyber attack.


With an understanding of vulnerabilities and risks, organizations can determine which issues need to be addressed first based on the criticality of the affected assets. Prioritization ensures that resources are allocated efficiently to reduce risks in a strategic manner. Factors like severity, exploitability, and business impact are all considered when prioritizing vulnerabilities.


The remediation process involves selecting and implementing solutions to eliminate or mitigate the vulnerabilities identified during the discovery and testing phases. This includes installing software patches, making configuration changes, decommissioning legacy systems, and deploying additional security controls. Remediation aims to methodically reduce an organization’s attack surface by fixing weaknesses and improving resiliency.

ASM and Its Role in Defeating Attackers

Attack Surface Management (ASM) takes a proactive approach to cybersecurity by focusing on vulnerabilities from an attacker’s perspective. Rather than waiting to respond to incidents, ASM aims to prevent them in the first place through continuous monitoring and remediation of the attack surface.

The attack surface refers to any point in an organization’s infrastructure, applications, or end user devices that could be exploited by malicious actors to compromise systems and data. By understanding the attack surface and how it is changing over time, security teams can identify and fix vulnerabilities before attackers have a chance to leverage them.

Continuous Mapping and Monitoring

ASM relies on automated tools to continuously discover and map the evolving attack surface, including internal and external-facing assets. Monitoring the attack surface ensures new vulnerabilities are detected quickly so they can be prioritized and remediated based on the level of risk. As new assets are added or configurations change, the tools rescan to update the organization’s attack surface map.

Prioritizing Risks That Matter

Not all vulnerabilities pose the same level of risk. ASM helps organizations focus on fixing serious weaknesses first by evaluating vulnerabilities based on factors like:

  • Severity (how much damage could be caused if exploited)
  • Exploitability (how easy it is for attackers to leverage the vulnerability)
  • Exposure (whether the vulnerability is externally facing)
  • Asset criticality (how important the vulnerable system is)

By prioritizing vulnerabilities in this way, security teams can allocate resources to address the risks that matter most.

Reducing the Window of Opportunity

Attackers often exploit vulnerabilities within days or even hours of their disclosure. ASM aims to shrink the window of opportunity by enabling organizations to quickly identify and remediate serious weaknesses. The faster vulnerabilities can be fixed, the less time attackers have to leverage them for malicious purposes like infiltrating networks, stealing data, or holding systems for ransom.

In summary, ASM takes a proactive and risk-based approach to security that focuses on vulnerabilities from an attacker’s perspective. By continuously monitoring the attack surface, security teams can identify and fix critical weaknesses before they are exploited. This helps reduce risk and close the window of opportunity for attackers.

How to Identify Your Organization’s Attack Surface

To effectively manage an organization’s attack surface, IT and cybersecurity professionals first need to identify what constitutes that surface. An organization’s attack surface encompasses all the vulnerabilities and weaknesses that malicious actors could potentially exploit to compromise systems and data.

The attack surface includes both external-facing and internal components. Externally, the attack surface consists of the organization’s online presence, including its website(s), web applications, and any other internet-connected systems. These provide potential entry points for cybercriminals to gain access to networks and data. Internally, the attack surface includes all networked systems, servers, endpoints, applications, and databases within the organization. Vulnerabilities in any of these components could be leveraged to pivot deeper into networks or access sensitive information.

Some of the specific assets that make up an organization’s attack surface include:

  • Public IP addresses and domains
  • Email servers and accounts
  • VPNs and other remote access systems
  • Firewalls, routers, and other network infrastructure
  • Physical access control systems
  • Employee endpoints like laptops, desktops, and mobile devices
  • Internal applications and databases
  • Cloud infrastructure and services
  • IoT and OT devices

To identify the full attack surface, IT and cybersecurity teams should conduct regular audits and assessments of all internal and external systems and components. Vulnerability scanning tools can help automate the discovery of vulnerabilities and misconfigurations across the organization. Penetration testing and red team exercises also provide valuable insights into potential attack vectors and entry points.

Continuously monitoring the attack surface is key to minimizing risks. As the organization’s infrastructure, applications, and workforce evolve, new vulnerabilities and security gaps may emerge. Proactively identifying these changes helps ensure the attack surface remains as small as possible.

Best Practices for Managing Your Attack Surface

To effectively manage an organization’s attack surface, cyber security professionals recommend several best practices.

First, conduct routine audits and assessments of the attack surface. This includes identifying all internet-facing assets like servers, cloud resources, and web applications. It also means finding vulnerabilities that could be exploited as well as sensitive data that needs protection. Regular attack surface assessments allow organizations to gain visibility into the scope of their digital footprint and prioritize risks.

Second, minimize the attack surface area when possible. This can be done by removing unused internet-facing assets, closing down vulnerable ports and protocols, and implementing the principle of least privilege to limit access. Reducing the number of entry points and access helps cut down opportunities for compromise.

Third, continuously monitor the attack surface for changes and emerging threats. New assets, accounts, and software get added frequently, and vulnerabilities are discovered all the time. Constant monitoring, along with tools like security information and event management (SIEM) solutions, can quickly detect modifications to the attack surface and new risks. Organizations can then respond promptly to address them.

Fourth, enforce strong security controls and risk mitigation. This includes implementing multi-factor authentication, keeping systems and software up to date with the latest patches, restricting access to sensitive data, and training users on security best practices. Robust controls significantly reduce vulnerabilities and the impact of potential attacks.

Finally, communicate attack surface management policies and procedures to all relevant personnel. Everyone, from C-level executives to IT administrators to end users, must understand their role in identifying and managing the attack surface. Promoting a culture of shared responsibility for cyber risk mitigation helps to shrink the overall attack surface.

Following these recommendations can help organizations take a proactive approach to attack surface management. Regular assessment, monitoring, control, and communication are all required to gain visibility and minimize vulnerabilities across the digital footprint. With diligent effort, companies can identify and fix weaknesses before they are exploited.

What is External Attack Surface Management?

External Attack Surface Management (EASM) refers to the process of identifying, analyzing, and securing the exposed assets and vulnerabilities of an organization that are accessible from the internet. Unlike internal attack surface management, which focuses on internal networks and systems, EASM deals with the parts of a company’s network that are exposed to the outside world. This includes websites, web applications, cloud services, and other internet-facing assets.

Key components of EASM include:

  • Asset Discovery and Inventory: Identifying all external digital assets associated with an organization. This not only includes known assets but also unknown or forgotten assets such as outdated web applications or domains.
  • Vulnerability Detection and Assessment: Analyzing these assets for vulnerabilities or misconfigurations that could be exploited by attackers. This step often involves scanning for known vulnerabilities, checking for proper configurations, and assessing for other security risks.
  • Prioritization and Risk Assessment: Not all vulnerabilities pose the same level of risk. EASM involves assessing the risk level of different vulnerabilities, taking into account factors like the potential impact of a breach and the likelihood of exploitation.
  • Remediation and Mitigation: Addressing identified vulnerabilities, which can involve patching software, updating configurations, or even removing unnecessary services.
  • Continuous Monitoring and Improvement: The external attack surface is not static; it evolves as new services are deployed, existing services are updated, and new vulnerabilities are discovered. Continuous monitoring is essential for ensuring that new risks are identified and addressed promptly.
  • Reporting and Compliance: Documenting the organization’s external attack surface and the measures taken to secure it, which can be crucial for compliance with various cybersecurity standards and regulations.

Implementing an Attack Surface Management Program

To implement an effective attack surface management program, organizations should take a proactive and ongoing approach.

A critical first step is to gain visibility into the organization’s current attack surface and cyber risk exposure. This includes identifying and documenting all internet-facing assets like servers, web applications, remote access points, and cloud resources. It also means analyzing vulnerabilities and weaknesses in configurations or software that could be exploited. Regular scans and audits of networks and systems are needed to maintain an up-to-date inventory and assess risks.

With visibility and risk awareness established, controls and safeguards must be put in place to reduce the attack surface. This could include closing unneeded open ports, patching known vulnerabilities, enabling multi-factor authentication, restricting access, and hardening systems and software. Strict configuration standards should be set and enforced to minimize weaknesses.

Continuous monitoring is required to ensure the attack surface remains minimized over time as networks, systems, software, and user access change. New vulnerabilities may emerge, configurations can drift out of compliance, and accounts or access may become orphaned. Attack surface management tools can help automate the monitoring of controls and risk metrics. Alerts notify security teams if attack surface metrics start to trend in an unfavorable direction so issues can be promptly addressed.

A well-developed attack surface management program will also include defined processes for risk acceptance, exception management and change control. Some amount of risk may need to be accepted due to business requirements. Exceptions should be documented and approved, with compensating controls in place if possible. And all changes to networks, systems, software or access should follow a standardized change management process that considers attack surface implications and cyber risks.

Through vigilance and the consistent application of attack surface management principles, organizations can take a proactive stance in reducing their cyber exposure and risk of a successful attack. But in today’s dynamic environments, the work is never done – continuous improvement and adaptation are needed to manage the persistent threats.


To summarize, attack surface management is a vital cybersecurity discipline that helps organizations understand and reduce the ways that attackers can compromise systems and data.

By gaining visibility into vulnerabilities and misconfigurations across networks, applications, endpoints and users, security teams can take a risk-based approach to prioritizing and remediating issues.

With a comprehensive and continuous attack surface management program in place, companies can dramatically strengthen their security posture and reduce risks in today’s expanding threat landscape.

Though not a simple process, attack surface management yields benefits that make the investment of time and resources well worth the effort for any organization serious about cyber risk mitigation.