Moving systems into the cloud can improve flexibility, scalability and access, but it doesn’t automatically make them secure. So, what is cloud security testing? Put simply, it’s the process of assessing your cloud infrastructure, applications, identities and configurations to uncover weaknesses that could lead to unauthorised access, data exposure or a wider compromise.

The challenge is that cloud security isn’t controlled entirely by Amazon Web Services, Microsoft Azure, Google Cloud or whichever provider you use. Under the shared responsibility model, some protections sit with the provider while others remain your responsibility. The NCSC points out that customers are always responsible for securely configuring the cloud services they choose and deciding what data they store within them.

That creates room for problems such as excessive permissions, exposed services and vulnerable applications, particularly as environments change over time. In this guide, we’ll explain what cloud security testing covers, how it differs from cloud penetration testing and when a deeper cloud security assessment makes sense.

What Does Cloud Security Testing Actually Cover?

There’s no single cloud security test that tells you whether an entire environment is secure.

Instead, testing looks across different layers of your cloud infrastructure to identify vulnerabilities and understand how they might interact. The exact scope depends on the cloud services you’re running, the data they handle and how the environment has been built.

One of the first areas we’d look at is identity and access management (IAM). Cloud environments rely heavily on permissions, roles and service identities. A user might have more access than they need, an old account may still be active or one service could be allowed to assume a much more privileged role.

Those issues aren’t theoretical. Google Cloud’s H1 2026 Threat Horizons report found that identity issues were involved in initial access in 83% of incidents involving major cloud and SaaS-hosted environments investigated by Mandiant during the second half of 2025. Data was targeted in 73% of cloud-related incidents.

Cloud configurations are another major focus. Testing might check whether storage is publicly accessible, firewall rules are too broad, encryption is configured correctly or logging has been disabled. The NCSC recommends periodically auditing cloud configurations as part of a broader security assessment or penetration test because secure defaults and best practice can change over time.

Applications and APIs also need attention. Putting an application in Azure or AWS doesn’t remove vulnerabilities within the application itself. Authentication weaknesses, insecure APIs, exposed secrets or poor authorisation controls can still give an attacker a route into cloud resources.

Depending on your setup, a cloud vulnerability assessment may also examine containers, Kubernetes, serverless functions, virtual machines and Infrastructure as Code templates.

That last point is easy to overlook. If an insecure configuration appears in a Terraform template, for example, automation tools can reproduce the same weakness across multiple environments. Automation isn’t inherently a security benefit. It simply makes both good and bad configurations easier to scale.

Why Is Cloud Security Testing Important?

Cloud security testing provides something that dashboards and policies alone can’t always give you: evidence that your controls work as expected.

It’s possible for an organisation to have security measures in place while still leaving a practical route open to an attacker. MFA may be enabled for most users, for example, while a forgotten service account retains powerful permissions. A database might not be directly exposed to the internet, but an externally accessible application could have credentials capable of reaching it.

Individually, findings like these can appear relatively unremarkable. When they’re connected, the risk can look very different.

This is why we prefer to think about attack paths, rather than simply counting vulnerabilities. One exposed resource combined with an overprivileged identity and access to sensitive data may deserve much more attention than a longer list of isolated low-risk findings.

The wider threat landscape reinforces the need to validate vulnerabilities properly. Verizon’s 2026 Data Breach Investigations Report found that exploitation of vulnerabilities had become the most common initial access vector in its dataset, accounting for 31% of breaches.

For security teams, the goal shouldn’t therefore be to produce the largest possible spreadsheet of alerts. Effective testing ensures findings are understood in context so remediation can focus on weaknesses that could genuinely affect the business.

When Do You Need Cloud Security Testing?

There isn’t a universal rule saying every organisation needs the same test every three months.

A better approach is to base your testing frequency on how quickly the environment changes, what it’s exposed to and the consequences if something goes wrong.

A cloud security assessment is particularly worthwhile around a major migration. Moving workloads from an internal network into cloud infrastructure changes trust boundaries, access controls and often the way applications communicate. Testing helps confirm that security assumptions made before the migration still hold afterwards.

The same applies after significant architectural changes. Adding Kubernetes, moving to serverless infrastructure, introducing a new API or connecting another cloud provider can all create new attack paths.

Testing is also sensible before launching an internet-facing service that handles sensitive information. You don’t want the first meaningful test of your access controls to come from someone trying to break into them.

Following a security incident, another assessment can be valuable. Fixing the vulnerability that was exploited isn’t always enough. You also need to establish whether similar weaknesses exist elsewhere and whether the original route has genuinely been closed.

Compliance can create additional testing requirements. Frameworks and standards such as PCI DSS may require regular vulnerability management and penetration testing in relevant environments. However, we’d be cautious about treating compliance as proof of security. Passing a prescribed check doesn’t necessarily mean an attacker couldn’t find another route through the environment.

For fast-moving cloud native environments, continuous automated checks make sense alongside periodic human-led testing. The NCSC recommends periodic automated configuration tests as well as penetration testing that includes cloud platform configuration.

In practical terms, the faster your infrastructure changes, the shorter the shelf life of your last security assessment becomes.

Cloud Security Testing vs Cloud Penetration Testing

Cloud security testing and cloud penetration testing are closely related, but they aren’t interchangeable.

Cloud security testing is the wider discipline. It can include vulnerability scanning, configuration reviews, IAM analysis, compliance testing and cloud security posture management (CSPM).

Cloud penetration testing is more specifically concerned with exploitation.

Rather than simply identifying vulnerabilities or insecure cloud configurations, penetration testers attempt to establish what an attacker could actually achieve within an agreed scope.

A vulnerability scanner might flag an overly permissive IAM role. A penetration tester could go further by testing whether that role can be abused to escalate privileges, access another service or reach sensitive information.

That distinction becomes particularly important in environments already using CSPM or other automation tools. Continuous tooling is useful for spotting configuration drift and known weaknesses in real time, but automated results still need context.

Security practitioners regularly raise the same practical issue: individual findings can look relatively benign until relationships between identities, permissions and cloud services are examined together. One recent discussion among cloud security professionals described automated posture tools as useful for enumeration while highlighting the importance of understanding how separate IAM, storage and compute issues can chain into an attack path.

For most mature environments, we’d therefore view automation and human testing as complementary rather than competing approaches.

How Does a Cloud Security Test Work?

A useful cloud security test starts with scope, not scanning.

Before testing begins, we’d establish which accounts, subscriptions, applications and services are included. We’d also determine what level of access testers will receive and whether any production systems require additional restrictions.

From there, the environment can be mapped. This includes understanding internet-facing assets, identities, trust relationships, network routes and where sensitive information is stored.

Automated testing may then be used to identify known vulnerabilities and common configuration issues. Manual analysis can go deeper, particularly where several apparently separate weaknesses could create a more serious attack path.

Where cloud penetration testing is included, authorised testers may attempt controlled exploitation to answer questions such as:

• Can a low-privileged identity gain additional permissions?

• Can an exposed application be used to reach internal cloud services?

• Could a compromised account access data it shouldn’t be able to see?

• Are security controls capable of stopping or detecting realistic attack behaviour?

Findings should then be prioritised according to genuine risk rather than technical severity alone. A medium-rated weakness that gives an attacker access to a business-critical production system may warrant faster action than a higher-scoring vulnerability on an isolated test server.

Retesting is equally important. Changing a policy or closing a port doesn’t necessarily mean the entire attack path has disappeared.

There are also provider rules to consider. AWS currently allows customers to perform security assessments and penetration tests against a defined range of their own AWS services without prior approval, but testing AWS’s underlying infrastructure is prohibited and some activities require separate authorisation.

Microsoft similarly allows customers and authorised third parties to test Azure resources they own without pre-approval, provided testing follows Microsoft’s published Rules of Engagement.

A properly scoped test should account for those requirements before any offensive activity begins.

So, What Is Cloud Security Testing Really Trying to Prove?

The simplest answer to what cloud security testing is is that it’s a way of finding weaknesses in cloud environments. But we think there’s a more useful way of looking at it.

You’re really testing whether the assumptions behind your security still hold true.

Is that storage bucket genuinely private? Does that service account only have the permissions it needs? Can a supposedly isolated workload reach production data? Would an attacker who obtained one credential be contained, or could they move further through the environment?

Cloud environments rarely stand still. New services appear, permissions change and infrastructure is rebuilt automatically. As a result, security testing shouldn’t just confirm that your setup looked secure at one point in time.

Automated monitoring, configuration reviews and cloud vulnerability assessment can provide valuable continuous visibility. When you need to understand whether those weaknesses can be turned into a genuine attack path, human-led cloud penetration testing provides a deeper level of validation.

If you’d like to find out how well your cloud infrastructure would stand up to a real attack, speak to our team about a cloud security assessment or penetration test.