Cloud Security Audits: Step By Step

What is a Cloud Security Audit?

A cloud audit is a test of a cloud environment, typically conducted by an independent third-party. During an audit, the auditor gathers evidence via physical inspection, inquiry, observation, re-performance, or analytics. 

Cloud security audits commonly focus on an organization’s security controls – these are the operational, procedural, or technical protections an organization uses to safeguard the integrity and confidentiality of its information systems. In the cloud, an auditor may evaluate which security controls exist, whether they are implemented correctly, whether they are working as expected, and how effective they are at mitigating threats.

In addition, a cloud security audit typically verifies that cloud systems are aligned with the specific requirements of regulations, industry standards, or security benchmarks.

Benefits of Cloud Security Audits

Here are a few ways in which security audits can improve the security of your cloud environment:

• Overseeing access control – employees join and leave the organization and personnel move to new roles and departments. A security audit can ensure that access control is managed responsibly, for example ensuring that access is revoked when employees leave, and that new employees are granted minimal privileges. 
• Secure access to the cloud – a cloud security audit can help verify that employees and other users access cloud systems in a secure manner – for example, using a VPN over an encrypted channel.
• Security of APIs and third-party tools – most cloud environments use a large variety of APIs and third-party technologies. Every API or third-party tool is a potential security risk. Audits can identify security weaknesses in APIs and tools and help the organization remediate them.
• Verifying backup strategies – the cloud makes it easy to perform backups. However, this is only effective if an organization’s cloud platform is configured to carry out the backups regularly. An audit can ensure that the organization is performing backups for all critical systems, and adopting security measures to safeguard those backups. 

Cloud Security Auditing Challenges

Here are a few key challenges that can make cloud security audits more difficult, and how to overcome them.

Transparency

In a cloud environment, cloud providers control most of the operational and forensic data. This data is critical for auditing purposes. Audits must have a comprehensive inventory of cloud resources and data, access to security policies, and direct access to relevant forensic data. This requires coordination with cloud providers and the organization’s IT operations staff.

Encryption

There are a two main options for encrypting data in the cloud:

• You can encrypt data on-premises and then send it to the cloud, but this runs the risk of rogue insiders abusing their privileges.
• You can leave encryption to the cloud provider, but then you will be at risk of breaches within the cloud provider’s environment.

From an auditing perspective, it is almost always better to encrypt data on-premise and manage encryption keys in-house. Auditing can be extremely difficult, even impossible in some cases, if encryption keys are managed by the cloud provider. The PCI DSS Cloud Special Interest Group encourages organizations to store and manage encryption keys independently from the cloud provider. 

Colocation

In a cloud environment, it is very common for several environments to share the same physical systems. This creates security issues and makes it more difficult to audit the physical environment. If it is not possible to run services on physically separate devices, the cloud provider must provide proof that it can prevent any user of the system from gaining administrative privileges on the machine.

Scale, Scope, and Complexity

In a traditional data center, there was a finite number of servers, which auditors could review and report on. In a cloud environment, there can be exponential growth in the number of audited entities, which may include physical hosts, virtual machines (VMs), managed databases, containers, and serverless functions. It can be very difficult to audit all these entities, especially considering new entities are added and removed on a daily basis.

The key to making a cloud environment auditable is to standardize workloads. For example, if containers are only created using a limited, controlled set of images, auditors can focus their testing on those approved container images. Similarly, VMs should be created from a limited pool of machine images that can be reviewed by auditors.

Tips from the expert

Steve Moore is Vice President and Chief Security Strategist at Exabeam, helping drive solutions for threat detection and advising customers on security programs and breach response. He is the host of the “The New CISO Podcast,” a Forbes Tech Council member, and Co-founder of TEN18 at Exabeam.

In my experience, here are tips that can help you optimize your cloud security audit process:

Define audit scope with a focus on shared responsibility
Clarify the scope of your cloud security audit by explicitly defining the boundaries of your responsibility versus the cloud provider’s. This will streamline the audit process and help auditors focus on your areas of control, like data, workloads, and access management.

Automate cloud resource inventory
Use automated tools to maintain an up-to-date inventory of all cloud assets, including VMs, containers, and serverless functions. This ensures the audit can accurately assess the full scope of your cloud environment, even as new resources are dynamically added or removed.

Establish audit-ready logging and visibility
Ensure that logging is enabled for all critical cloud services, including authentication, data access, and configuration changes. Centralize logs using SIEM for easy access during audits and to maintain compliance with regulations like PCI DSS and HIPAA.

Integrate audit processes with DevSecOps pipelines
Build security checks into your CI/CD pipeline to ensure all deployed workloads meet security standards. This helps auditors verify that code and infrastructure changes follow organizational security policies without requiring manual intervention.

Adopt encryption best practices for auditability
Ensure that sensitive data is encrypted both at rest and in transit, with encryption keys managed independently from cloud providers. Use tools like AWS KMS or Azure Key Vault for encryption management, making it easier to audit key rotation and data protection practices.

6 Steps to Conducting a Cloud Security Audit

1. Evaluate the Cloud Provider’s Security Posture

The first step of a cloud security audit is evaluating the cloud provider’s security posture, and establishing a relationship with cloud provider staff to receive the necessary information. As part of your audit, evaluate security procedures and policies, and work to determine the risk inherent in cloud systems, based on reliable data from cloud systems.

2. Determine The Attack Surface

Cloud environments are complex and have low visibility. Use modern cloud monitoring and observability technology to identify the attack surface, prioritize assets at higher risk, and focus remediation efforts.

Understand what applications are running within cloud instances and containers, and whether they are approved by the organization, or represent shadow IT. All workloads must be standardized and must have the appropriate security measures to ensure compliance.

This type of monitoring can address the difficulties of the shared responsibility model, by providing visibility into the security profile of the cloud assets you manage on an ongoing basis.

3. Set Strong Access Controls

Access management breaches are one of the most prevalent cloud security risks. There are many ways in which credentials to critical cloud resources can fall into the wrong hands. Here are some steps you can take to minimize risk from your side:

• Create strong password standards and policies
• Make multi-factor authentication (MFA) a must
• Limit administrative privileges
• Practice the least privilege principle for all cloud assets

4. Develop External Sharing Standards

You must implement standards for data sharing via shared drives, calendars, files, and folders. The best approach is to begin with the strictest standards and loosen security restrictions if there is a special need.

Folders and files featuring the most sensitive data, including personally identifiable information (PII), financial, and protected medical information (PHI), should not be permitted for external access and sharing, except in special circumstances.

5. Automate Patching

You should regularly patch to ensure your cloud environment is secure. However, mastering patch management can be challenging for security and IT teams. Multiple studies found that it takes organizations over a month on average to patch a security weakness.

The key to effective patching is to prioritize the most important patches, and ensure that critical assets are patched automatically on a regular basis. Complement automation with regular manual reviews to ensure that patching mechanisms are functioning properly.

6. Use SIEM to Standardize Cloud Logs

Security information and event management (SIEM) systems can help organizations comply with many industry standards and regulations. Log management, a function of SIEM, is an industry-standard approach for auditing activity on an IT network. SIEM systems can collect cloud logs in a standardized format, and allow editors to explore log data, and automatically generate reports needed for various compliance standards.

Exabeam: Enhancing Threat Detection with Advanced Security Analytics

The Exabeam Security Operations Platform delivers a powerful combination of SIEM, behavioral analytics, automation, and network visibility to transform how organizations detect, investigate, and respond to threats. By correlating firewall logs with data from endpoints, cloud environments, identity systems, and other security sources, Exabeam provides deeper insights into evolving threats that would otherwise go undetected.

Behavior-driven analytics enable Exabeam to go beyond static rules and signatures, identifying anomalous activity that indicates credential misuse, insider threats, or lateral movement across the network. By analyzing normal user and entity behavior over time, Exabeam surfaces high-risk activities that traditional security tools may overlook.

Automated investigations streamline security operations by linking disparate data points into comprehensive threat timelines, reducing the time analysts spend piecing together incidents manually. This allows teams to quickly identify the root cause of an attack and respond with precision.

Learn more about Exabeam SIEM