Attack Surface Assessment – A 101 Guide

Discover how attack surface assessment reveals security vulnerabilities. This guide covers methods, steps, benefits, challenges, and best practices to protect your digital assets.

With the evolution and the expansion of the digital footprint of any organization through hosting remote work solutions, cloud-based services, or interconnected systems, the entry points for potential attacks also increase. The growing number of potential access points creates an attack surface, which is the overall sum of all the possible points where an unauthorized user can enter an environment to gain access to data or extract data from an environment.

For organizations looking to secure their digital assets, attack surface assessment (ASA) is an essential practice. The security teams can help reduce the mean time to discover an attack by getting a strong grip on the attack surface and complete visibility of every single aspect of it, including its vulnerability management aspect. This enables organizations to transition from reactive response to prevention via strategic security prioritization and resource allocation.

In this blog, we will discuss attack surface assessment, its importance, and its benefits and challenges. We will also explore the processes that can aid an organization in defending its IT assets against a more sophisticated threat landscape.

What is Attack Surface Assessment?

Attack surface assessment is a methodical approach to discovering, identifying, and analyzing all points (the publicly visible ones) in an organization’s IT infrastructure (including hardware, software, and digital solutions) where a potential threat actor can gain access to the organization for malicious reasons. This includes enumerating all the access points to a given system, such as network ports, application interfaces, user portals, APIs, and physical access points. The end result is a composite view of where an organization may be susceptible to attack.

An attack surface assessment is an evaluation of the technical and non-technical components of the environment. This encompasses hardware devices, software applications, network services, protocols, and user accounts. The non-technical part pertains to the human aspect, organizational processes, and physical security. Together, they provide a complete picture of an organization’s security posture and identify target areas for remediation.

Why Conduct Attack Surface Assessments?

Organizations can not protect what they are unaware of. Security breaches happen on abandoned systems, as unknown assets, or using out-of-scope access points that security teams had never thought to include in their protection plans.

Once organizations know how an attacker can get in, they can identify the weak spots, whether that’s out-of-date software, missing patches, ineffective authentication mechanisms, or interfaces that aren’t well defended. This gives security teams the window to patch these vulnerabilities before an attacker can exploit them.

Most organizations work in a never-ending loop when responding to security alerts and incidents. Teams are burnt out, and organizations are exposed. This pattern is altered by attack surface assessments as teams can discover and resolve vulnerabilities before they are exploited.

Common Assessment Methodologies for ASA

Security teams use different methodologies to evaluate and manage their attack surface effectively. The approach an organization selects usually depends on its security needs, available resources, and complexity of the digital environment.

Automated discovery techniques

Automated discovery techniques are the backbone of most attack surface assessment programs. These tools use scanning networks, systems, and applications to detect both assets and vulnerabilities with minimal human effort. Port scanners map open network services, subdomain enumeration tools find dormant web properties, and configuration analyzers look for insecure configurations.

Manual verification processes

Automation gives width, and manual verification processes give depth to the attack surface assessments. This involves manual review of critical systems, access controls testing, and security architecture assessment to identify issues that an automated tool would miss, such as business process logical flaws, authentication bypass techniques, and access permissions review by security professionals.

Continuous vs. point-in-time assessment

When designing their security programs, organizations must choose between continuous monitoring and point-in-time assessments. Snapshot security evaluations, known as point-in-time assessments, are frequently conducted quarterly or annually. These assessments tend to be thorough analyses but might miss newer vulnerabilities that are present during assessing cycles. In contrast, continuous monitoring always checks for new assets, configuration changes, or vulnerability.

Risk-based prioritization frameworks

Risk-based prioritization frameworks allow security teams to prioritize the most critical items first. These frameworks take into account potential breach impact, likelihood of exploitability, and business value of impacted assets. A risk-based approach allows security teams to address the biggest vulnerabilities first, rather than just the highest volume or most recently disclosed.

Offensive security perspective applications

This offensive security approach to attack surface assessment presents an opportunity for a better understanding of actual attack paths. This approach is where security teams think like an attacker, testing systems how an attacker would. These include attack path mapping, mapping chains of vulnerabilities leading to a major breach, and adversary emulation, where teams emulate the technology used by particular threat groups.

How to Perform Attack Surface Assessment?

An efficient attack surface assessment must be systematic, blending both technical tools and strategic logical ability. Here is the process that describes the basic steps organizations need to follow in order to evaluate their security posture and learn their weak points.

Initial scoping and objective setting

All good attack surface assessments should have some goals and scope. In this phase, security teams specify which systems will be examined, what kind of security flaws they are seeking, and what constitutes a successful assessment. This planning phase will define if the assessment is looking at specific critical assets, newly deployed systems, or the entire organization.

Asset enumeration and discovery phase

Identifying and registering every system, application, and service that comprises the digital presence of the enterprise forms the focus of this phase. The process of discovery starts with passive and active methods. These passive methods might include reading all existing documentation, network diagram analysis, DNS record checks, and searching public databases for perceived organization assets.

Mapping of External Attack Vectors

After identifying assets, security teams turn their attention to knowing how cyber criminals could gain access to these systems externally. This step analyzes the multiple routes that an attacker can take to obtain initial access. External attack vector mapping is the process of establishing a detailed mapping of all connection points to the outside world from internal systems. This encompasses all services that are exposed onto the internet, VPN endpoints, email gateways, and third-party connections.

Identification of Internet-facing services and applications

Any system that has a direct or indirect (set up via a VPN tunnel, etc.) connection to the Internet is the number one target by its nature and requires special attention during the assessment. In this step, all the services that one can directly access through the public internet should be examined thoroughly. Teams scan all published IP ranges and domains for open ports and running services.

Evaluating Authentication and Access Control Systems

Failure of access controls that keep out unauthorized users will let any user in, even on well-protected systems. This part is the way to determine how users are validating their identity and what users have access to the resources. The authentication assessment includes checking password policies, two-factor authentication, session handling, and credential storage.

Documenting Findings and Creating Risk Profiles

The last step involves converting the technical findings into executable security intelligence by documenting vulnerabilities and evaluating their impact on the business. Remediation planning and overall security improvement will be based on this documentation. Teams write a technical description of each vulnerability, outline its potential impact, and explain how easily it could be exploited.

Attack Surface Assessment Benefits

Attack surface assessments provide organizations with a significant amount of value aside from vulnerability identification. The systematic framework for security analysis gives rise to several benefits that contribute resiliency and operational efficiency to an enterprise security posture.

Enhanced visibility

Regular attack surface assessments enhance visibility in complex environments. As organizations evolve, it becomes increasingly difficult for them to have and retain an accurate understanding of the IT assets they possess. Shadow IT, legacy systems, and rogue applications create blind spots where security risks can go undetected. Security teams can then see and secure their whole environment.

Reduce incident response costs

Early detection of vulnerabilities mitigates incident response costs greatly with attack surface assessments. The longer hackers remain undetected, the more costly security incidents become. By identifying vulnerabilities proactively through a vulnerability assessment, one can identify vulnerabilities before an attacker does, allowing for remediation to take place before breach response, customer notification, system recovery, and regulatory fines become an issue.

Strategic resource allocation

These assessments also help organizations concentrate their security spending where needed, allowing for more strategic allocation of resources. Nowadays, there is pressure on security teams to protect more systems than ever and do it with limited resources. The information provided in attack surface assessments is critical for decision-makers as it identifies exactly what systems are the highest risk and which vulnerabilities pose the greatest potential damage if exploited.

Business expansion ease

Pre-deployment security analysis enhances business expansion security. As organizations innovate new products, expand to new markets, or introduce new technologies, they also provide new attack vectors. Before these expansions, conducting attack surface assessments addresses security threats with a proactive approach because these threats tend to be more easy and cost-efficient to fix early in the process.

Challenges in Attack Surface Assessment

The attack surface assessment deliverables are undoubtedly valuable to security teams, but there are also a number of uniquely large challenges associated with the implementation and maintenance of an attack surface assessment program. When organizations recognize these challenges, they can create better considerations for assessments and reset goals.

Dynamic and evolving IT environments

For security teams, it is difficult to maintain pace with constant changes, particularly in organizations with active development teams and frequent releases. There is a gap between the fluid nature of modern infrastructure and the tools/processes designed to observe it. New deployments bring additional potential attack vectors, and decommissioned systems often leave abandoned resources still accessible.

Cloud and containerized infrastructure complexity

Assessment tools built for regular on-prem infrastructure tend to have little visibility into cloud-based risks such as misconfigured storage buckets, excessive IAM permissions, or insecure serverless functions. Containerized applications add another level of complexity with their multi-tier ambient orchestration systems and registry security aspects.

Maintaining accurate asset inventory

Asset discovery tools often overlook systems or do not provide them with complete information. Shadow IT resources deployed without security team awareness become blind spots of security coverage. Legacy systems are seldom documented, which means their function and relationships are not always obvious.

Resource constraints and prioritization

There is a problem with the tools, expertise, and time that drive resource challenges. Most teams do not have the advanced expertise required to evaluate cloud environments, IoT devices, or specialized applications. Assessment tools have substantial price tags, which may be more than the budget allocated for it. Business units often apply time pressure, leading to shortened assessments that can miss critical vulnerabilities.

False positive management

Finding insights requires security teams to review and validate the findings manually, which, depending on the scale of assessment, can take hours to days. The frequent false alerts make it easy for analysts to become desensitized to them, and they may miss genuine threats hidden among them. In the absence of processes for triaging and validating results, teams become buried under the avalanche of information.

Best Practices for Attack Surface Assessment

Many organizations should understand the best practices for successful attack surface assessment in order to avoid common pitfalls and achieve maximum security value.

Establishing a comprehensive asset inventory

A complete and accurate asset inventory is the foundation of effective attack surface management. For organizations to secure assets, they first need to know what they have. Leading organizations maintain asset inventories of all hardware, software, cloud resources, and digital services.

Implementing continuous monitoring

In all the infrastructure, deploy sensors to capture the security telemetry that includes vulnerability data and configuration changes as well as suspicious activity. Automatically check that the current state matches expected baselines and alert on deviations using orchestration tools, along with continuous vulnerability scanning with no fixed schedule.

Contextualizing findings with threat intelligence

Security teams should join threat feeds for details on the vulnerabilities that are actively being exploited, emerging techniques, and industry-specific thread topics. Correlate the organization’s attack surface discoveries to this intelligence to see which vulnerabilities are most likely to be exploited in the near future. Monitor threat actor campaigns that may target the industry or companies that look like similar organizational profiles to understand report likely attack paths.

Risk-Based Remediation Prioritization

Create an issue ranking based on a scoring system that factors in vulnerability severity, asset criticality, exploitability, and data sensitivity. Focus on vulnerabilities that are easy to exploit and provide an attacker access to sensitive systems or data. Develop various remediation timelines based on the business value at risk, for example, ensuring critical issues are remediated in a matter of days and lower-risk artifacts are captured in regular maintenance/patch cycles.

Stakeholder Communication and Reporting

Write executive reports that distil technical findings into business risk terms covering potential operational, financial, and reputational impacts. Create IT-specific technical reports that contain remediation steps to be taken along with information on checkpoints to confirm this.

Real-World Examples of Attack Surface Exposure

The 2017 Equifax breach is one of the biggest instances of attack surface exposure with devastating results. This involved attackers using an unpatched vulnerability in Apache Struts, a web application framework, to breach Equifax systems. Although this vulnerability was already public and a patch was available, Equifax did not apply the patch throughout their environment. It was this oversight that gave the attackers access to the sensitive consumer credit data of around 147 million people.

In 2019, the Capital One breach happened when an ex-employee of AWS exploited a misconfigured WAF in Capital One’s AWS environment. The misconfiguration allowed an attacker to execute commands on the metadata service and retrieve credentials to access S3 bucket data. The hack compromised around 100 million Americans and around 6 million Canadians. It is a good example of how deceptively complicated cloud environment security is and how important cloud configuration management is.

Conclusion

In the modern and evolving threat landscape, organizations need to adopt various strategies to protect their digital assets, hence, attack surface assessment. By conducting structured identification, analysis, and remediation of possible places to enter, security teams can greatly minimize their risk of cyberattack. Frequent assessments allow for fixing any problems before attackers can find and exploit them. This proactive measure enhances security but also helps the compliance process and resource allocation and contributes to security strategy insights.

FAQs

What is an attack surface assessment?

An attack surface assessment is a process of identifying, documenting, and analyzing all possible points of entry into an organization’s IT infrastructure that may be exploited by attackers. This includes tracking everything from hardware to software to network services that may act as an entry point for hackers or unwanted users.

What are the key components of an attack surface?

In any attack surface, the key components include internet-facing applications and services, network perimeters, endpoints and user devices, cloud resources, third-party connections, APIs, user accounts, and physical access points. All of these components serve as potential entry points for attackers.

How does an attack surface assessment differ from a vulnerability assessment?

An attack surface assessment identifies every possible entry and access vector, while a vulnerability assessment examines only known vulnerabilities in these entry points. While attack surface assessment tackles questions around what is being attacked, vulnerability assessment digs deeper into how it can be attacked.

What are common attack vectors identified in an attack surface assessment?

Unpatched software, misconfigured cloud services, disclosures of the API, broken authentication systems, users susceptible to phishing, insecure or unnecessary network services, default credentials, and supply chains from third parties are all common attack vectors. These vectors illustrate the routes that attackers actually take when they try to break into the system.

How often should an organization conduct an attack surface assessment?

Organizations should conduct a full attack surface assessment at least once a quarter and proactively monitor in between major assessments. In high-change environments or in heavily regulated industries, an assessment is needed more often. It should also assess any major infrastructure change.

Can attack surface assessment help prevent cyberattacks?

Yes, attack surface assessment can help prevent cyberattacks by identifying and remediating vulnerabilities before attackers can exploit them. By understanding where they are exposed, organizations can implement targeted security controls, reduce their attack surface, and make themselves less attractive targets for attackers.