Access controls are the aspect of Software as a Service (SaaS) functionality and operations that the cloud customer is responsible for and should be audited. Access controls refer to the methods and techniques that verify the identity and access rights of users or devices that access or use the SaaS application and its data. Access controls may include credentials, policies, roles, permissions, tokens, multifactor authentication, single sign-on, etc. The cloud customer is responsible for ensuring that only authorized and legitimate users or devices can access or use the SaaS application and its data, as well as for protecting the confidentiality, integrity, and availability of their data. The cloud customer should also monitor and audit the access and usage of the SaaS application and its data, as well as any incidents or issues that may affect them123.

Source code reviews (A) are not the aspect of SaaS functionality and operations that the cloud customer is responsible for and should be audited. Source code reviews refer to the processes and practices that examine the source code of software applications or systems to identify errors, bugs, vulnerabilities, or inefficiencies that may affect their quality, functionality, or security. Source code reviews are mainly under the responsibility of the cloud service provider, as they own and operate the software applications or systems that deliver SaaS services. The cloud customer has no access or control over these aspects123.

Patching (B) is not the aspect of SaaS functionality and operations that the cloud customer is responsible for and should be audited. Patching refers to the processes and practices that ensure the security, reliability, and performance of the cloud infrastructure, platform, or software. Patching involves the use of updates or fixes to address vulnerabilities, bugs, errors, or exploits that may compromise or affect the functionality of the cloud components. Patching is mainly under the responsibility of the cloud service provider, as they own and operate the cloud infrastructure, platform, or software. The cloud customer has limited or no access or control over these aspects123.

Vulnerability management (D) is not the aspect of SaaS functionality and operations that the cloud customer is responsible for and should be audited. Vulnerability management refers to the processes and practices that identify, assess, treat, monitor, and report on the risks that affect the security posture of an organization or a domain. Vulnerability management involves the use of tools or techniques to scan, analyze, prioritize, remediate, or mitigate vulnerabilities that may expose an organization or a domain to threats or attacks. Vulnerability management is mainly under the responsibility of the cloud service provider, as they own and operate the cloud infrastructure, platform, or software. The cloud customer has limited or no access or control over these aspects123. References :=

Cloud Audits: A Guide for Cloud Service Providers - Cloud Standards …

Cloud Audits: A Guide for Cloud Service Customers - Cloud Standards …

Cloud Auditing Knowledge: Preparing for the CCAK Certificate Exam