Increasing digitalization and connectivity mean most organizations are facing a growing attack surface. As a result, there are more IT assets to track and manage, plus more potential attack routes for threat actors to target. The threat situation is constantly evolving, especially in the area of vulnerabilities – last year alone, over 30,000 new vulnerabilities were published. So, how can you keep track of your external attack surface to understand where it might be open to exploitation?

An effective way to assess and improve your overall cybersecurity posture is to conduct an attack surface evaluation and get an ‘attack surface score’. We’ll explain why your attack surface score is worth knowing and even show you how to get a free attack surface analysis.

What is an attack surface score? 

How well is your organization’s online infrastructure secured and maintained? Is your cybersecurity hygiene up to standard? How do you compare to other companies in your industry?
These are critical questions – and with attack surface scoring, you can answer them with data.

An attack surface score provides a comprehensive assessment of your organization’s total external attack surface. It evaluates key cybersecurity factors across technical, human, procedural, regulatory, organizational, and physical domains. Each of these is essential for safeguarding the confidentiality, integrity, and availability of your systems and data. This evaluation helps identify vulnerabilities, prioritize remediation efforts, and ultimately strengthen your organization’s cyber resilience.

How is the attack surface score calculated? 

The attack surface score is the result of a complex attack surface evaluation that considers and weighs multiple areas of an organization’s attack surface. The best way to perform an attack surface assessment and calculate your score is through an External Attack Surface Management (EASM) solution.

A score is set and maintained on three levels:

1. Asset: Each asset (i.e. a website, (sub)domain, IP host or certificate) receives a score across the six dimensions explained below.
2. Scope: In an EASM dashboard, you can view the aggregated score for the entire attack surface scope. Here, you get an overview of the prioritized observations or issues per dimension and quickly see which issues need to be fixed to improve the score.
3. Observation: Each observation is linked with a certain security dimension and is scored within this dimension.

Calculating your attack surface score with EASM

Outpost24’s EASM solution calculates both a total attack surface score and individual scores across six key cybersecurity dimensions. This comprehensive attack surface assessment combines the scores of all identified assets and security dimensions to deliver an accurate picture of your overall cybersecurity posture.

The scoring uses a weighted average approach, where lower-performing areas are given greater weight. This means critical weaknesses have a stronger impact on the final score and are prioritized accordingly.

Here are the six dimensions we measure:

1. Identification of the attack surface 

First, all internet-connected assets and resources are identified. This includes web servers, cloud services, network devices, and other digital components that can be potential points of attack. EASM solutions are able to discover both known and unknown internet-facing assets.

Vulnerability assessment 

This is followed by a thorough analysis of all vulnerabilities, including known vulnerabilities in software versions, missing patches, and configuration issues. Each vulnerability is weighted according to its risk. 

Vulnerabilities are reported when Oupost24 finds software versions that have known vulnerabilities. As we take a strong discovery approach, the EASM asset discovery accuracy and completeness is best-in-class, increasing the yield in finding many exposed CVEs, including infrastructure and (3rd party) web application technologies. The average score for this dimension is C and can be improved by updating software versions.

2. Analysis of the configuration 

The EASM solution verifies that IT resources are configured according to established security policies. This includes evaluating security headers, access controls, and implementing authentication methods. Missing or weak SPF and DMARC records also fall in this category.

On average, an organization scores a D for this dimension. Score improvement is achieved by actions such as configuring all records correctly and only setting cookies after user consent is received.

3. Assessment of exposed services 

Applications or services that are accidentally or intentionally accessible directly via the internet are evaluated. These include protocols for authentication and authorization, and the need to take certain services offline or implement access restrictions. Better and more secure architectures and setups exist to securely make use of these services.

This dimension also tends to score a D. This score can be improved by taking the service offline or whitelisting the access.

4. Encryption check 

The validity and strength of encryption, especially SSL certificates, is checked. This ensures that all connections are secure and protected from man-in-the-middle attacks. A man-in-the-middle attack is a cyberattack in which an attacker secretly intercepts or alters communications between two parties in order to steal or manipulate sensitive information.

This is the worst scoring dimension, with an average of E. Improving this score can be realized by securing all connections with up-to-date protocols and making sure every website has a valid and unexpired SSL certificate.

5. Reputation monitoring 

Reputation is usually the best scoring cybersecurity dimension. In these EASM checks, the reputation of discovered IP addresses is verified in external spam and blocklist security services. Reputation issues can lead to service degradation and performance issues.

Although the average score is A for this dimension, there is still some room to improve. You can check why your asset is blocklisted, solve the problem and notify the entity blocking you. Alternatively you can set up a new host – that is not blocklisted – after solving the problem.

6. Cyber hygiene evaluation 

The overall cyber hygiene of the digital environment is assessed, including the management of outdated websites, unused or expired domains, and unnecessary digital footprints. 

Hygiene based risks usually have a low priority, and are not a direct cybersecurity risk. They can be sources for information gathering, or point to online assets that are not setup according to standards, or possible candidates for taking offline.

Although not high in priority in terms of risk, the first line of defense against bad actors remains reducing your attack surface and keeping it clean. Therefore, this dimension cannot be underestimated and points out quick wins and forgotten, outdated assets.

Search for compromised credentials 

In addition, Outpost24’s EASM solution integrates Threat Intelligence to check whether there are leaked credentials from users linked to your domains online. 

Why is it valuable to know your attack surface score?

Performing regular attack surface evaluations enables your team to maintain full visibility and identify areas for proactive remediation. Here are some of the key benefits provided by knowing and understanding your attack surface score:

1. More insights and easy to consume information: The six dimensions each give more insights into the entire attack surface, explaining where to look for problems in your attack surface and how to address them in the remediation phase. A bad score means you have an opportunity to take actions and improve the score. The dimensions represent Oupost24’s suggestions to clean up the attack surface.
2. Easier prioritization and workflow: The score tells you where to start. When you know what issues to focus on, you can prioritize the ones to fix first. Instead of having a long flat list to sift through, you can now start with the dimensions that score the worst. The Oupost24 EASM platform guides you on where to focus first.
3. Reporting: Your attack surface score offers a measurable way to track security performance and clearly communicate improvements in your organization’s online presence to management. This makes it easier to demonstrate progress, justify investments, and align cybersecurity efforts with business goals.
4. Save time: Ultimately, it all leads to greater efficiency. You gain faster, more actionable insights, significantly reducing Mean Time to Detect (MTTD). Because the Outpost24 EASM Platform is purpose-built for attack surface management, you can spend less time on discovery and more time on remediation – resolving issues quickly and strengthening your organization’s cyber resilience.
5. Historical trend: The trendline in the scoring feature provides a historic overview of the evolution of your attack surface score over time. This long-term visibility allows you to track progress, measure the impact of remediation efforts, and identify recurring issues that may need strategic attention. It also helps demonstrate progress to stakeholders and auditors.

Early detection of cybersecurity risks and increased cyber resilience 

By continuously monitoring and tracking the external attack surface, including all internet-connected assets and their security status, organizations can identify vulnerabilities before they are exploited by attackers. Continuous monitoring and improvement of the attack surface increases an organization’s cyber resilience.

A reduced and well-managed attack surface means that it becomes more difficult for attackers to penetrate the system. It also makes the company more resilient to cyberattacks by minimizing potential entry points and strengthening security protocols. 

Attack surface score benchmarking

Outpost24’s EASM has a ‘Score Benchmark’ feature that offers an additional scoring analysis of all assets of the external attack surface. It delivers real-time data on customers’ observed risks and associated priorities, compared to the average score of other scopes in the EASM platform combined with industry benchmarks.

The score benchmark acts as a crystal-clear window into your security posture, enabling you to gauge your resilience against potential threats. 

• It provides a tangible metric to demonstrate due diligence to clients, auditors, and partners. 
• You can measure the effectiveness of your security initiatives and adapt and allocate resources based on real-time data.
• It delivers a clear assessment of an organization’s security posture compared to industry standards.
• It helps you to set realistic goals to continuously improve the security posture of your company.

How does your external attack surface perform? 

The attack surface score is an indispensable tool for modern companies that take their cybersecurity seriously. It provides a clear and measurable assessment of the security posture, enables effective prioritization of actions, and helps increase cyber resilience.

With Outpost24’s EASM solution, organizations can easily track their external attack surface in real time and respond to changes before they escalate into threats. Get started with your free attack surface assessment today and take the first step toward better cyber resilience.