External Attack Surface Assessment
Your organisation may expose more systems and services to the internet than internal teams realise. Websites, cloud applications, remote-access services, email infrastructure, forgotten test environments, and systems managed by third parties can all become visible entry points for attackers.
The challenge is that an organisation’s external environment changes constantly. New services are introduced, cloud resources are created, domains are registered, and temporary systems remain online longer than intended. Traditional asset lists do not always reflect what is actually accessible from outside.
An External Attack Surface Assessment from CA shows how your organisation appears from an attacker’s perspective. We identify internet-facing assets, examine their exposure, and highlight weaknesses that could provide an initial route into your systems or data.
Why This Matters
Attackers do not limit their search to the systems included in your official inventory. They scan domains, IP addresses, cloud services, remote-access gateways, exposed applications, and other online resources for weaknesses they can exploit.
An unknown or forgotten asset can be particularly risky because it may not receive regular updates, security monitoring, or management attention. Even a system that is no longer important to the business can become a route into connected services.
An external attack surface assessment helps you:
Discover unknown assets
Identify internet-facing systems, domains, services, and cloud resources that may not appear in your current asset inventory.
Find exposed weaknesses
Recognise vulnerable software, insecure configurations, unnecessary services, expired certificates, and publicly accessible administrative interfaces.
Understand what attackers can see
Review your external environment from outside the organisation, without relying only on internal records or assumptions.
Prioritise the most important risks
Focus attention on exposures that are most likely to be exploited or could create the greatest business impact.
Our Approach
We do not begin with the assumption that the existing asset register is complete. We use the organisation’s known domains, addresses, brands, and digital relationships as starting points, then investigate the wider external environment.
The assessment combines asset discovery, technical review, vulnerability analysis, business context, and practical validation. We distinguish genuine risks from irrelevant results so that internal teams receive a manageable and useful set of findings.
External attack surface management is specifically concerned with identifying, monitoring, and reducing weaknesses in internet-accessible assets. It provides defenders with an external view similar to the one available to potential attackers.
Establish the scope and known digital footprint
We begin by understanding your organisation, brands, business locations, public services, subsidiaries, acquisitions, and important technology providers.
We collect the known domains, subdomains, public IP ranges, websites, cloud services, remote-access systems, and externally hosted applications that should form part of the assessment.
We also discuss recent changes that may have expanded the external environment. These could include cloud migrations, new customer platforms, mergers, development projects, supplier changes, or services introduced by individual business units.
This provides an initial reference point while allowing the assessment to look beyond the assets already known to internal teams.
Discover and map internet-facing assets
We examine the organisation’s visible digital footprint to identify assets and relationships associated with it.
The discovery process may identify websites, APIs, email services, VPN gateways, remote desktop services, cloud-hosted systems, storage resources, certificates, name servers, and third-party technologies. We also look for forgotten development environments, old domains, exposed management services, and systems that no longer have a clear owner.
Potential assets are validated before being included in the results. This reduces the risk of assigning unrelated infrastructure to your organisation or asking teams to investigate findings that do not belong to them.
The outcome is a clearer and more accurate view of the systems visible from the public internet.
Assess exposure and validate weaknesses
We examine identified assets for security weaknesses and signs of unnecessary exposure.
This may include vulnerable or unsupported software, insecure protocols, weak encryption, exposed administrative interfaces, configuration errors, expired certificates, publicly accessible storage, information leakage, and services that should not be reachable from the internet.
Findings are reviewed to understand whether they present a genuine risk. We consider the type of system, the information it processes, available security controls, possible attack routes, and whether the weakness could realistically be exploited.
Unsupported internet-facing edge devices require particular attention because unresolved vulnerabilities may provide attackers with an entry point into otherwise supported environments.
Prioritise remediation and support ongoing visibility
We organise findings according to their technical severity, exploitability, level of exposure, business importance, and potential impact.
Each confirmed issue includes a clear explanation of the risk and a practical recommended action. This may involve applying an update, changing a configuration, restricting access, renewing a certificate, removing an unnecessary service, or confirming ownership of an unknown asset.
We also identify gaps in asset-management and change-management processes that allowed the exposure to develop. Where required, CA can help establish ongoing monitoring so that new assets and changes to the external environment are identified earlier.
What Sets CA Apart
An attacker’s view of your environment
We assess what is visible from outside the organisation rather than relying exclusively on internal inventories.
Validated and relevant findings
We investigate discovered assets and weaknesses to reduce false positives and avoid overwhelming teams with low-value results.
Priorities based on business risk
We consider the importance of the affected service and the likely business consequences, not only a technical severity score.
Support beyond asset discovery
We provide practical remediation recommendations and help improve the processes used to manage the external environment over time.
The Business Value
An External Attack Surface Assessment from CA gives your organisation a clearer understanding of the systems and services that attackers can see and potentially target.
Previously unknown or forgotten assets can be brought under proper ownership and management. Unnecessary services can be removed, exposed systems can be secured, and serious weaknesses can be addressed before they provide an easy route into the organisation.
The assessment also improves the quality of your asset information. Security, IT, cloud, and business teams gain a more consistent view of which external services exist, why they are needed, and who is responsible for them.
The result is a smaller and better-controlled external attack surface, clearer remediation priorities, and a lower likelihood that an unmanaged system becomes the starting point for a significant incident.
Next Step
You cannot protect an internet-facing asset if your organisation does not know that it exists.
Contact CA for an initial consultation. We will help you map your external digital footprint, identify exposed weaknesses, and develop a practical plan for reducing the risks attackers can see from outside your organisation.