How to Perform Cloud Penetration Testing in AWS

The rise in cybercrime and the ongoing migration of services to the cloud have made cloud penetration testing one of the most critical components in any organisation's cybersecurity strategy.

As businesses increasingly rely on Amazon Web Services AWS for scalability and efficiency, their attack surfaces also grow. This blog post is designed for IT professionals, cybersecurity practitioners and businesses who want to understand how to evaluate their AWS environments for vulnerabilities. By the end of this guide, readers will understand the core risks associated with cloud infrastructure, how to test for them and what best practices to follow for a secure AWS setup.

Cloud penetration testing involves simulating cyberattacks on a cloud environment to identify and remediate vulnerabilities before real attackers can exploit them. In AWS this means testing various cloud components such as EC2 S3 IAM and networking configurations for security weaknesses. Think of it as a fire drill for your cloud systems ensuring all security alarms and controls function as intended.

For example if an organisation stores sensitive data in an S3 bucket but misconfigures access permissions that data could be publicly accessible without anyone knowing. Cloud pen testing would identify this exposure allowing quick remediation.

This is important now more than ever as regulatory pressure grows and cyberattacks become more advanced. Misconfigurations in cloud setups continue to be a leading cause of data breaches making proactive testing essential.

AWS follows a shared responsibility model where AWS manages the security of the cloud while customers manage security in the cloud. This means AWS secures the infrastructure hardware and networking but it is the customer’s job to secure their applications data and configurations.

For example AWS is responsible for the physical security of data centres and network infrastructure. However users must configure IAM policies correctly apply encryption to data and set up proper firewall rules. Failure to understand this model leads to gaps in security posture especially when teams assume AWS covers more than it actually does.

This model is crucial for penetration testers as it defines the boundaries of what can be tested. Testers must ensure they do not violate AWS policies and should focus on areas under customer control such as IAM configurations S3 permissions and EC2 settings.

Before starting a cloud penetration test it is vital to define the scope and obtain proper authorisation. AWS requires prior notice and strict adherence to its Acceptable Use Policy. Penetration testing without permission may result in account suspension or legal repercussions.

Scope should include details about which services will be tested what type of tests will be conducted and which data is off-limits. This ensures clarity and protects both the tester and the organisation. It is also important to identify tools and platforms that comply with AWS’s testing guidelines.

Pre-engagement also involves risk assessments and setting expectations for potential downtime or service disruption. Documentation should be prepared in advance to record findings and remediation steps.

Enumeration is the first step in identifying what services and resources exist in the AWS environment. This involves both passive and active techniques to gather information without disrupting services.

Passive enumeration may involve querying public DNS records or metadata to infer information about infrastructure. Active enumeration includes using tools such as AWS CLI Amass or Recon-ng to gather data about EC2 instances security groups IAM users and S3 buckets.

Tools like CloudMapper or ScoutSuite can provide visual representations of cloud architecture and highlight areas of concern. The aim is to identify entry points publicly exposed assets and overprivileged accounts which could be used by attackers.

Cloud environments face many risks due to their complexity. As organisations scale their infrastructure and adopt a variety of services, the number of potential security gaps increases. One of the biggest challenges in AWS environments is misconfiguration, which continues to be a leading cause of data breaches.

IAM misconfigurations are among the most critical vulnerabilities. These often involve users having excessive permissions that go beyond their job requirements. A lack of proper role separation makes it easy for a compromised account to gain broader access across services. In many cases, organisations also fail to enforce Multi-Factor Authentication (MFA), which is a simple but vital security measure. Without MFA, attackers who obtain credentials can access accounts unchallenged.

Public S3 buckets are another frequent issue. AWS S3 is commonly used to store files, backups and sensitive business data. However, if the access control settings are misconfigured, these buckets can become publicly accessible. This exposes private information to anyone on the internet, often without the knowledge of the organisation.

Security group errors can be equally damaging. Security groups act like virtual firewalls, and overly permissive rules can leave ports and protocols open to exploitation. For example, exposing SSH or RDP ports to the internet without restrictions invites brute-force attacks.

Open APIs and Lambda functions are powerful tools, but if left unauthenticated or misconfigured, they can serve as hidden entry points for attackers. These components should always be protected with authentication and rate limiting.

The Capital One data breach is a stark reminder of what can happen when misconfigurations go unchecked. In that case, overly broad IAM roles and an exposed API led to the compromise of over 100 million customer records. This incident highlights why proactive testing for misconfigurations must be a core part of any cloud security strategy.

Cloud environments face many risks due to their complexity. As organisations scale their infrastructure and adopt a variety of services, the number of potential security gaps increases. One of the biggest challenges in AWS environments is misconfiguration, which continues to be a leading cause of data breaches.

IAM misconfigurations are among the most critical vulnerabilities. These often involve users having excessive permissions that go beyond their job requirements. A lack of proper role separation makes it easy for a compromised account to gain broader access across services. In many cases, organisations also fail to enforce Multi-Factor Authentication (MFA), which is a simple but vital security measure. Without MFA, attackers who obtain credentials can access accounts unchallenged.

Public S3 buckets are another frequent issue. AWS S3 is commonly used to store files, backups and sensitive business data. However, if the access control settings are misconfigured, these buckets can become publicly accessible. This exposes private information to anyone on the internet, often without the knowledge of the organisation.

Security group errors can be equally damaging. Security groups act like virtual firewalls, and overly permissive rules can leave ports and protocols open to exploitation. For example, exposing SSH or RDP ports to the internet without restrictions invites brute-force attacks.

Open APIs and Lambda functions are powerful tools, but if left unauthenticated or misconfigured, they can serve as hidden entry points for attackers. These components should always be protected with authentication and rate limiting.

The Capital One data breach is a stark reminder of what can happen when misconfigurations go unchecked. In that case, overly broad IAM roles and an exposed API led to the compromise of over 100 million customer records. This incident highlights why proactive testing for misconfigurations must be a core part of any cloud security strategy.

A variety of tools are available to assist with AWS penetration testing. Each offers different capabilities, and when used together, they provide a comprehensive overview of an organisation’s security posture.

Pacu is an open-source AWS exploitation framework designed for simulating real-world attack scenarios. It allows penetration testers to test privilege escalation paths, identify misconfigured roles and policies, and validate potential attack chains in a controlled manner. This is ideal for red teaming and security research.

ScoutSuite is a powerful multi-cloud auditing tool that aggregates cloud configurations and produces insightful reports. For AWS environments, it highlights security issues like weak IAM policies, open S3 buckets, and unencrypted data stores. The visual interface helps teams quickly prioritise what to fix.

Prowler is a command-line tool that performs security assessments based on AWS security best practices and compliance requirements. It checks for things like logging configurations, IAM policies, and open ports. Prowler is widely used for continuous compliance monitoring and audit readiness.

CloudSploit is a SaaS-based tool designed to detect misconfigurations in AWS environments. It supports real-time monitoring and provides clear recommendations for remediation. This tool is particularly useful for DevOps teams looking to embed security into their workflows.

AWS Inspector is a native AWS service that automatically assesses applications for vulnerabilities and deviations from best practices. It is easy to integrate with other AWS services and is useful for both development and production environments.

Using these tools not only helps to identify vulnerabilities but also ensures organisations stay compliant with internal and external security standards. It is recommended that testing be carried out on a regular basis, especially after significant changes to infrastructure. When these tools are used in conjunction with expert analysis, they form a strong foundation for cloud security testing.

Cloud environments face many risks due to their complexity. As organisations scale their infrastructure and adopt a variety of services, the number of potential security gaps increases. One of the biggest challenges in AWS environments is misconfiguration, which continues to be a leading cause of data breaches.

IAM misconfigurations are among the most critical vulnerabilities. These often involve users having excessive permissions that go beyond their job requirements. A lack of proper role separation makes it easy for a compromised account to gain broader access across services. In many cases, organisations also fail to enforce Multi-Factor Authentication (MFA), which is a simple but vital security measure. Without MFA, attackers who obtain credentials can access accounts unchallenged.

IAM misconfigurations are among the most serious issues in AWS. These include granting users administrative privileges without justification, failing to rotate access keys, and neglecting MFA enforcement. In many cases, organisations retain inactive or unused IAM users that still have active credentials. These dormant accounts can become prime targets for attackers who scan for weak points in IAM policies.

Attackers often use privilege escalation paths to move laterally within an environment. For instance, if a user has permission to create IAM roles and attach policies, they could silently elevate their access. In other cases, misconfigured trust policies can allow cross-account access, further expanding the attack surface.

Testing should involve reviewing IAM policies for adherence to the principle of least privilege. Overuse of wildcards such as "*" in policies can grant unintended permissions. Missing conditions or lack of identity-based controls can also weaken security. IAM Access Analyzer is a valuable AWS-native tool for identifying policies that allow unintended access. Manual inspection of trust relationships, inline policies, and session permissions is essential to ensure all access paths are intentional and secure.

A strong IAM strategy should also include regular audits, automated policy reviews, and enforcement of password policies and MFA. These steps significantly reduce the chance of privilege abuse or accidental data exposure.