In situations where Infrastructure as a Service (IaaS) cloud service providers do not permit on-premise audits, auditors must adapt by utilizing alternative sources of data to evaluate the customer's controls. This can include using automated tools, third-party certifications, and other forms of assurance provided by the service provider. This approach ensures that the auditor can still assess the security posture and compliance of the cloud services without direct physical access to the provider's infrastructure.
References = The Cloud Security Alliance (CSA) provides guidelines on effective cloud auditing practices, including the use of alternative data sources when on-premise audits are not feasible1. Additionally, discussions on the Certificate of Cloud Auditing Knowledge (CCAK) highlight the importance of adapting audit strategies to the cloud environment2.