The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are implemented and managed between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and the operating system and middleware. The CSC, however, retains responsibility for the security *in* the cloud, which encompasses their applications, data, and user access management.

In the context of a PaaS model, the CSC is typically responsible for configuring security settings related to the application environment, managing user identities and access, and ensuring the security of the data they store and process within the PaaS. The CSP manages the patching of the operating system and middleware, the physical security of the data centers, and the network infrastructure. Therefore, a security incident involving a vulnerability in the PaaS platform’s operating system would primarily fall under the CSP’s responsibility for remediation, although the CSC would need to cooperate and potentially implement compensating controls if the vulnerability impacts their specific deployment. Conversely, a data breach due to misconfigured access controls on the CSC’s application data would be the CSC’s responsibility.

The question probes the understanding of this division of responsibility, specifically within the PaaS context, and how it relates to incident response and control implementation. The correct answer reflects the CSC’s accountability for securing their deployed applications and data, including the configuration of security settings that govern access and data protection within the PaaS environment.

The core principle being tested here is the shared responsibility model as it applies to cloud security, specifically within the context of ISO 27017. When a cloud service provider (CSP) offers a Platform as a Service (PaaS) offering, the responsibility for securing the underlying infrastructure, including physical security of data centers, network infrastructure, and the hypervisor layer, rests with the CSP. The customer, in this PaaS scenario, is responsible for securing their applications, data, access management to those applications, and the configuration of the PaaS environment as it pertains to their specific deployment. ISO 27017 emphasizes that controls are allocated between the cloud service customer and the cloud service provider based on the type of cloud service. For PaaS, the provider manages the foundational elements, while the customer manages the operational aspects of their deployed services and data. Therefore, the customer’s responsibility extends to the security of their deployed code, the data processed by that code, and the access controls governing who can interact with these elements. The CSP’s obligation is to ensure the integrity and availability of the platform itself.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their infrastructure. The CSP is operating under the framework of ISO 27017:2015. A critical aspect of cloud security, particularly for CSPs, is the management of security incidents and the subsequent communication with customers. ISO 27017:2015, in conjunction with ISO 27001, mandates specific controls related to incident management and communication. Control A.16.1.7, “Reporting of information security events,” and A.16.1.5, “Assessment and decision on information security events,” are foundational. However, the specific requirement for informing affected customers about a breach, especially when it involves personal data, is often driven by broader regulatory frameworks that ISO 27017 complements. Considering the global landscape of data protection, regulations like the GDPR (General Data Protection Regulation) impose strict notification timelines and content requirements for data breaches. While ISO 27017 provides the security controls, the legal and contractual obligations for customer notification are paramount. Therefore, the CSP’s primary obligation, beyond internal incident handling, is to adhere to the notification requirements stipulated by applicable data protection laws, which often dictate the timing and content of such communications to affected individuals. This includes providing details about the nature of the breach, the types of data compromised, and the measures being taken. The correct approach prioritizes fulfilling these external legal and contractual obligations to ensure transparency and compliance, which is a core tenet of responsible cloud service provision under the ISO 27017 standard.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC uses a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and hypervisor. The CSC, however, is responsible for security *in* the cloud, which encompasses their data, applications, operating systems, identity and access management, and network configurations within the PaaS environment. Specifically, ISO 27017:2015 clause 6.3.1, “Responsibilities for cloud services,” emphasizes that the CSC must understand and manage the security responsibilities allocated to them. In a PaaS scenario, the CSC is typically responsible for securing the operating system and middleware they deploy, as well as the applications and data residing on them. Therefore, the CSC must implement appropriate controls for data protection, access management to their applications, and secure configuration of the provided platform services. The CSP handles the physical security of the data centers, network infrastructure, and the virtualization layer. The question probes the CSC’s responsibility for securing the operating system and applications within a PaaS environment, which aligns with the standard’s delineation of duties.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). Clause 5.1.1, “Roles and responsibilities,” and Annex A, specifically controls related to customer responsibilities in a cloud environment, are crucial here. When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for securing the underlying infrastructure, operating system, and middleware. The CSC, however, retains responsibility for securing their applications, data, and user access management within that PaaS environment. Therefore, a CSC implementing a new customer-facing web application on a PaaS must ensure that the application itself is developed with secure coding practices, that sensitive data processed by the application is encrypted at rest and in transit, and that robust authentication and authorization mechanisms are in place for users accessing the application. The CSP handles the patching of the operating system and middleware, but the CSC is accountable for the security posture of the application code and the data it manages. This distinction is fundamental to managing cloud security risks effectively and aligns with the principle of shared responsibility.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017. When a cloud service customer (CSC) uses a cloud service, the responsibility for security controls is divided between the cloud service provider (CSP) and the CSC. ISO 27017:2015, in Annex A, provides guidance on controls applicable to cloud services. Control A.8.1.2, “Information security for use of cloud services,” emphasizes the CSC’s responsibility for managing the security of data and access within the cloud environment. This includes implementing appropriate access controls, data classification, and ensuring secure configurations for the services they consume. The scenario describes a situation where a CSC has outsourced the development of a custom application to a third-party developer. While the CSP provides the underlying infrastructure, the CSC retains the ultimate responsibility for the security of their data and the application’s secure development lifecycle, including ensuring that the developer adheres to secure coding practices and that the application itself is secured against common vulnerabilities. The CSP’s responsibility is limited to the security *of* the cloud, not the security *in* the cloud as it pertains to the CSC’s specific data and applications. Therefore, the CSC must ensure that the third-party developer implements security measures that align with the CSC’s own security policies and the requirements of ISO 27017, particularly concerning data protection and secure application development. The responsibility for securing the application code and its deployment within the cloud environment, as well as managing the access rights of the developer to the CSC’s data, falls squarely on the CSC.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC uses a Platform as a Service (PaaS) offering, the CSP is responsible for securing the underlying infrastructure, operating system, and middleware. The CSC, however, retains responsibility for securing their applications, data, identity and access management for their users, and network configurations within the PaaS environment. Specifically, ISO 27017:2015 clause 6.3.1, “Responsibilities for controls,” emphasizes this division. In a PaaS scenario, the CSP manages the physical security of data centers, network infrastructure, and the operating system. The CSC is responsible for configuring security settings related to their deployed applications, managing user access to these applications, encrypting sensitive data before it is stored or transmitted, and implementing security measures for any custom code or configurations they deploy. Therefore, the CSC’s responsibility extends to the security *of* their data and applications *within* the PaaS environment, not the security *of* the PaaS environment itself, which is largely managed by the CSP. The question probes the understanding of this delineation, particularly in the context of PaaS. The correct answer reflects the CSC’s accountability for their own data and application security within the provided platform.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and virtualization layers. The CSC, however, retains responsibility for security *in* the cloud, which encompasses the applications they deploy, the data they store, and how they configure the PaaS environment. Specifically, within a PaaS model, the CSP manages the operating system, middleware, and runtime environments. The CSC is accountable for managing user access to the PaaS, securing the data processed and stored within the platform, and ensuring the secure configuration of the deployed applications. Therefore, the CSC’s responsibility extends to the security of their deployed applications and the data they manage within the PaaS. This aligns with the principle that the CSC is responsible for what they put into the cloud and how they configure it, while the CSP is responsible for the foundational infrastructure.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). Clause 5.1.1, “Roles and responsibilities,” emphasizes the need for clear definition and documentation of these responsibilities. When a CSC migrates a legacy application to a Platform as a Service (PaaS) offering, the CSP typically manages the underlying infrastructure, operating system, and middleware. The CSC, however, retains responsibility for the application itself, its data, and user access management. Specifically, in a PaaS model, the CSC is responsible for securing the application code, configuring security settings within the PaaS environment (e.g., access controls for the application), and managing the data stored and processed by the application. The CSP is responsible for the security *of* the cloud infrastructure, including physical security, network security up to the hypervisor, and the security of the operating system and middleware that the CSC utilizes. Therefore, the CSC’s primary responsibility in this scenario, as per the standard’s guidance on shared responsibility, is to ensure the security of the application and its data, including the implementation of appropriate access controls and vulnerability management for the application code. This aligns with the principle that the CSC is responsible for what they put into the cloud and how they configure it.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it relates to ISO 27017:2015. When a cloud service customer (CSC) utilizes a cloud service, certain security responsibilities are inherently transferred to the cloud service provider (CSP). However, the CSC retains responsibility for securing data within the cloud environment and for the configuration and management of the services they consume. ISO 27017:2015 Clause 5.1.1, “Roles and responsibilities,” emphasizes the need for clear definition and documentation of these responsibilities. In the context of a data breach originating from an improperly configured virtual machine (VM) by the CSC, the CSC remains accountable for the security of their data and the configuration of their deployed resources. The CSP’s responsibility typically extends to the security *of* the cloud infrastructure, not the security *in* the cloud as configured by the customer. Therefore, the CSC’s failure to implement appropriate access controls and patching on their VM, leading to unauthorized access and data exfiltration, falls under their purview of responsibility. The CSP would only be implicated if the breach was due to a vulnerability in the underlying cloud infrastructure provided by the CSP, which is not indicated in the scenario. The CSC’s proactive security measures, such as vulnerability management and access control, are critical to mitigating such risks.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing and the specific controls that address cloud security. When a cloud service customer (CSC) utilizes a cloud service provider (CSP) for infrastructure as a service (IaaS), the responsibility for securing the operating system, middleware, and applications typically rests with the CSC. The CSP is generally responsible for the security of the underlying physical infrastructure and the virtualization layer. Therefore, if a vulnerability is discovered in the operating system deployed by the CSC within their IaaS environment, the CSC is primarily responsible for patching and mitigating that vulnerability. This aligns with the principle that the CSC has control over and responsibility for the components they deploy and manage within the cloud infrastructure. The standard emphasizes clear delineation of responsibilities to avoid security gaps.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and the operating system. The CSC, however, retains responsibility for security *in* the cloud, which encompasses the applications they develop and deploy, the data they store, and how they configure the PaaS environment. Specifically, for a PaaS offering, the CSC is accountable for securing their own code, managing access to their applications, protecting the data processed by those applications, and ensuring the secure configuration of the PaaS services they utilize. The CSP manages the underlying infrastructure, including patching the operating system and ensuring the physical security of the data centers. Therefore, the CSC’s responsibility extends to the logical separation of their data and applications from other tenants, the secure development lifecycle of their software, and the management of user identities and access controls for their specific services. The shared responsibility model is not static; it shifts based on the cloud service model (IaaS, PaaS, SaaS). In PaaS, the CSP’s responsibility boundary extends higher up the stack compared to IaaS, but the CSC always retains ultimate responsibility for their data and the security of their applications.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017:2015. In a cloud service arrangement, the cloud service provider (CSP) is responsible for the security *of* the cloud, while the customer is responsible for security *in* the cloud. ISO 27017:2015 provides guidance on controls for both parties. When a customer utilizes a Platform as a Service (PaaS) offering, the CSP manages the underlying infrastructure, operating system, and middleware. The customer, however, is typically responsible for the security of their applications, data, and identity and access management within that PaaS environment. Therefore, the customer’s responsibility extends to ensuring that the configurations of the provided services, such as database access controls and application deployment security, are robust and align with their organizational security policies and any relevant regulatory requirements like GDPR or HIPAA, which mandate specific data protection measures. The CSP’s role is to provide a secure platform, but the ultimate security posture of the deployed services and data rests with the customer.

The core principle being tested here is the shared responsibility model as it applies to cloud security, specifically within the context of ISO 27017:2015. The standard emphasizes that both the cloud service provider (CSP) and the cloud service customer (CSC) have distinct but overlapping responsibilities. When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP typically manages the underlying infrastructure, operating systems, and middleware. The CSC, however, retains responsibility for the security of their applications, data, and user access management within that PaaS environment. Therefore, the CSC must implement controls for data encryption, access control mechanisms for their applications, and secure configuration of the services they deploy. The CSP’s responsibility in this PaaS scenario would encompass the security of the underlying platform, including the operating system and network infrastructure, and ensuring the physical security of the data centers. The question probes the understanding of where the CSC’s direct control and therefore their primary security obligations lie in a PaaS model, aligning with the principles of ISO 27017:2015 which mandates clear delineation of responsibilities.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and virtualization layers. The CSC, however, is responsible for security *in* the cloud, which encompasses their data, applications, operating systems, identity and access management, and network configurations within the PaaS environment. Specifically, the CSC must ensure the secure configuration and management of the operating systems they deploy, the applications they develop and run, and the data they store and process. They also retain responsibility for managing user access and ensuring the security of their own endpoints. Therefore, in a PaaS model, the CSC’s direct responsibilities include the security of the operating system and application layers, as well as the data processed and stored.

The core principle being tested here is the shared responsibility model in cloud computing as it pertains to ISO 27017:2015, specifically concerning the customer’s obligations for data protection and access management within a cloud service. When a cloud service customer (CSC) utilizes a cloud service, the responsibility for securing the data stored and processed within that service is divided between the cloud service provider (CSP) and the CSC. ISO 27017:2015, in Annex A.5.1.1, emphasizes that the CSC is responsible for managing access to cloud services and the data within them. This includes defining user roles, granting and revoking permissions, and ensuring that only authorized personnel can access sensitive information. The CSP is responsible for the security *of* the cloud infrastructure, while the CSC is responsible for security *in* the cloud. Therefore, implementing robust identity and access management (IAM) controls, including multi-factor authentication and least privilege principles, falls squarely within the CSC’s domain. The scenario highlights a potential breach stemming from inadequate access controls, which is a direct consequence of the CSC not fulfilling its responsibilities in this area. The correct approach involves the CSC actively managing user access, implementing strong authentication mechanisms, and regularly reviewing access privileges to prevent unauthorized data exposure. This aligns with the standard’s guidance on protecting information and managing access rights.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017. When a cloud service customer (CSC) utilizes a cloud service, certain security responsibilities reside with the cloud service provider (CSP), while others remain with the CSC. ISO 27017 provides guidance on these responsibilities. In this scenario, the CSC is implementing a new application that requires specific network access controls and logging mechanisms for its internal operations. These are typically considered within the CSC’s domain of responsibility, as they relate to the configuration and operation of their specific workload and data. The CSP is responsible for the security *of* the cloud infrastructure (e.g., physical security of data centers, network infrastructure security up to the hypervisor or virtual network boundary, depending on the service model). However, the security *in* the cloud, which includes the configuration of virtual firewalls, access control lists for application traffic, and the detailed logging of application-level events, falls under the CSC’s purview. Therefore, the CSC must ensure that its security controls, including network segmentation and comprehensive logging, are implemented to meet its own security policies and any relevant regulatory requirements, such as those mandated by GDPR for data processing activities. The CSP’s role is to provide the secure underlying infrastructure and the tools to enable the CSC to implement these controls.

The core principle being tested here is the shared responsibility model as it applies to cloud security, specifically within the context of ISO 27017. When a cloud service customer (CSC) utilizes a cloud service, the responsibility for security is divided between the cloud service provider (CSP) and the CSC. ISO 27017 provides guidance on how this division of responsibility should be managed, particularly concerning the implementation of controls. In this scenario, the CSC is responsible for configuring the security settings of the virtual machines they deploy, including the network access control lists (ACLs) and firewall rules that govern inbound and outbound traffic. The CSP, on the other hand, is responsible for the security of the underlying cloud infrastructure, which includes the physical security of the data centers, the hypervisor, and the network fabric that supports the virtualized environment. Therefore, when a CSC observes unauthorized access to their virtual machine, the investigation and remediation efforts must focus on the controls within the CSC’s purview. The CSC must review their network ACLs, firewall configurations, and any access control mechanisms implemented within the operating system of the virtual machine. The CSP’s role would be to provide information about the security of the underlying infrastructure if there were indications of a compromise at that level, but the initial and primary responsibility for securing the virtual machine’s network access lies with the CSC. This aligns with the standard’s emphasis on clearly defining roles and responsibilities in the cloud security agreement.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are implemented and managed between the cloud service customer (CSC) and the cloud service provider (CSP). When a CSC uses a cloud service, certain security responsibilities are inherently transferred to the CSP, while others remain with the CSC. The standard emphasizes that the CSC must understand and document these responsibilities. Specifically, the standard requires the CSC to identify and document the security controls that are their responsibility, as well as those that are the CSP’s responsibility. This documentation is crucial for effective risk management and for ensuring that all necessary security measures are in place. The question probes the CSC’s obligation to maintain this clear delineation of responsibilities, which is a fundamental aspect of adopting cloud services securely under ISO 27017. The correct approach involves the CSC actively documenting and managing its own security responsibilities, rather than assuming the CSP handles all aspects or relying solely on the CSP’s documentation without independent verification and contextualization for their specific use case. This proactive stance ensures that the CSC’s unique security requirements and the specific implementation of cloud services are adequately addressed.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017. When a cloud service customer (CSC) utilizes a cloud service, certain security responsibilities are retained by the CSC, while others are delegated to the cloud service provider (CSP). ISO 27017, Annex A, Control A.3.4.1, “Information security in the development and maintenance of systems,” is particularly relevant. This control emphasizes that the CSC is responsible for the security of the applications and data it deploys within the cloud environment, including secure coding practices, vulnerability management of custom applications, and data protection mechanisms. The CSP, conversely, is responsible for the security of the underlying cloud infrastructure and services. Therefore, if a vulnerability is discovered within a custom-developed application that the CSC has deployed, the responsibility for patching and remediation lies with the CSC, as it falls under their management of the application layer and data. This aligns with the fundamental concept that the CSC retains control and accountability for their specific workloads and data, even when hosted on a CSP’s infrastructure. The other options represent a misunderstanding of this division of responsibility, either attributing the CSC’s application-level security to the CSP or misinterpreting the scope of shared responsibilities.

The scenario describes a cloud service provider (CSP) offering Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) to a customer. The customer is responsible for managing the operating system and applications, while the CSP manages the underlying infrastructure. ISO 27017:2015, specifically clause 6.3.1 (Information security for use of cloud services), emphasizes the shared responsibility model. This clause mandates that the CSP and the customer must define and document their respective responsibilities for information security. In this context, the CSP’s responsibility extends to the security of the cloud infrastructure itself, including the physical security of data centers, network security, and the hypervisor layer. The customer’s responsibility, given the IaaS/PaaS model, includes securing the operating systems, middleware, applications, and data they deploy. Therefore, the CSP’s obligation is to ensure the security of the foundational cloud environment that enables the customer’s services, rather than directly managing the customer’s specific application-level security configurations or data content. The correct approach is to ensure the CSP’s security controls are robust for the infrastructure they manage, which indirectly supports the customer’s security posture.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017. When a cloud service customer (CSC) utilizes a cloud service, certain security responsibilities remain with the CSC, even though the cloud service provider (CSP) manages the underlying infrastructure. ISO 27017 emphasizes that the CSC is responsible for the security of data processed within the cloud environment and for configuring security controls related to their specific services and applications. This includes ensuring that access controls are appropriately implemented for cloud-based services, managing user identities and permissions, and securing the data itself, whether at rest or in transit. The CSP’s responsibility typically extends to the security *of* the cloud, such as the physical security of data centers and the integrity of the cloud infrastructure. Therefore, when a data breach occurs due to misconfigured access controls on a customer-managed virtual machine or an improperly secured application deployed by the customer, the responsibility for that specific vulnerability lies with the CSC. This aligns with the standard’s guidance on defining roles and responsibilities in a cloud computing environment.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing and the specific controls that address cloud service customers (CSCs) and cloud service providers (CSPs). When a CSC uses a cloud service, certain security responsibilities are transferred to the CSP. However, the CSC retains ultimate accountability for its data and the security of its cloud-based systems. ISO 27017 provides guidance on how to map existing ISO 27001 controls to cloud environments and introduces new controls specifically for cloud security.

A key aspect is understanding which controls are typically the responsibility of the CSP and which remain with the CSC. For instance, the physical security of the data centers is a CSP responsibility, as is the security of the underlying cloud infrastructure (e.g., hypervisors, network fabric). Conversely, the CSC is responsible for managing access to its data and applications, securing its virtual machines and containers, and ensuring the security of its data within the cloud.

Considering a scenario where a CSC experiences a data breach originating from a compromised customer-managed virtual machine, the CSC would be primarily responsible for the incident response and remediation related to that VM. This includes identifying the root cause within the VM, containing the breach, eradicating the threat, and recovering the affected systems. While the CSP might provide logging and monitoring tools, or even assist in forensic analysis of the underlying infrastructure if requested and contractually agreed upon, the direct responsibility for the security posture of the customer-managed VM rests with the CSC. This aligns with the principle that the CSC is responsible for what it *configures* and *manages* within the cloud service. The question probes the understanding of this division of responsibility, particularly in the context of a breach originating from a customer-managed component. The correct answer reflects the CSC’s primary obligation for incident response concerning its own virtual machine.

The core principle being tested here is the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017. When a cloud service customer (CSC) utilizes a cloud service, the responsibility for security controls is divided between the cloud service provider (CSP) and the CSC. ISO 27017:2015, in Annex A.1.1.2, explicitly addresses the “Responsibility for cloud services.” It states that the CSC is responsible for the security of data processed in the cloud, the configuration of cloud services, and the security of their own user access and endpoints. The CSP is responsible for the security of the underlying cloud infrastructure and the services they provide. In the scenario presented, the CSC has implemented a new application that stores sensitive customer data. The responsibility for ensuring the security of this data, including its encryption at rest and in transit, and managing access controls to it, rests with the CSC. While the CSP provides the infrastructure, the CSC must configure and manage the security settings for their specific application and data. Therefore, the CSC is accountable for the security posture of their application and the data it handles, including implementing appropriate cryptographic controls and access management policies. This aligns with the fundamental concept that the CSC is responsible for what they put *in* the cloud, while the CSP is responsible for the security *of* the cloud.

The core of ISO 27017:2015 revolves around the shared responsibility model in cloud computing and the specific controls that address cloud service customers (CSCs) and cloud service providers (CSPs). When a CSC utilizes a cloud service, certain security responsibilities are transferred to the CSP. However, the CSC retains ultimate accountability for its data and the overall security posture. ISO 27017 provides guidance on how to manage these responsibilities effectively. Specifically, it emphasizes the need for clear contractual agreements that define the security responsibilities of both parties. For a CSC, understanding and implementing controls related to access management, data protection, and incident management within the cloud environment are paramount. The standard also highlights the importance of monitoring the CSP’s adherence to agreed-upon security measures. Therefore, a CSC’s primary focus, when considering the controls outlined in ISO 27017, should be on those that directly impact its ability to maintain control over its data and operations, even when relying on a CSP. This includes ensuring that the CSP’s security practices align with the CSC’s own security policies and regulatory requirements, such as those mandated by data privacy laws like GDPR or CCPA, which necessitate robust data protection measures regardless of the underlying infrastructure. The CSC must also ensure that it has the necessary visibility and audit capabilities to verify the CSP’s compliance.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and virtualization. The CSC, however, retains responsibility for security *in* the cloud, which encompasses the applications, data, identity and access management, and operating systems deployed on the PaaS. Specifically, the CSC is accountable for configuring and managing the security settings of the deployed applications, ensuring secure coding practices, managing user access to these applications, and protecting the data stored within them. The CSP’s responsibility extends to the security of the platform itself, including patching the underlying operating systems and middleware that the CSC’s applications run on, and ensuring the physical security of the data centers. Therefore, in a PaaS scenario, the CSC’s primary security obligations revolve around the application layer and the data it processes and stores, as well as the configuration of the platform services to meet their specific security requirements.

The core of ISO 27017:2015, particularly concerning the shared responsibility model in cloud computing, hinges on clearly delineating security obligations between the cloud service customer (CSC) and the cloud service provider (CSP). When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, network, and operating system. The CSC, however, retains responsibility for security *in* the cloud, which encompasses the applications, data, and identity and access management configurations deployed on the PaaS. Specifically, for a PaaS model, the CSC is accountable for securing their deployed applications, managing user access to these applications, and ensuring the confidentiality, integrity, and availability of the data they store and process within the PaaS environment. The CSP manages the underlying platform, including patching the operating system and middleware, and securing the network infrastructure. Therefore, the CSC’s primary responsibilities in this scenario revolve around their own digital assets and how they are managed within the provided platform.

The core of ISO 27017:2015 is the shared responsibility model in cloud computing, which dictates how security controls are allocated between the cloud service provider (CSP) and the cloud service customer (CSC). When a CSC uses a Platform as a Service (PaaS) offering, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, network, and virtualization layers. The CSC, however, is responsible for security *in* the cloud, which encompasses their data, applications, operating systems, identity and access management, and network configurations within the PaaS environment. Specifically, for a PaaS offering, the CSC typically manages the deployed applications, the data processed by those applications, and the configuration of the platform services they utilize. The CSP handles the physical security of data centers, network infrastructure, and the underlying operating systems and middleware that constitute the PaaS. Therefore, the CSC’s responsibility extends to ensuring the security of their deployed code, the data it handles, and the access controls to these components.

The core principle being tested here is the shared responsibility model in cloud computing as it pertains to ISO 27017. Specifically, it focuses on the customer’s responsibility for managing security within the virtual machine (VM) they deploy, even in an Infrastructure as a Service (IaaS) model. ISO 27017, in conjunction with ISO 27001, outlines controls for cloud security. Clause 5.3.1 of ISO 27017, “Information security in cloud services,” emphasizes the need for a clear definition of responsibilities between the cloud service provider (CSP) and the cloud service customer. In an IaaS scenario, the CSP is responsible for the security *of* the cloud (e.g., the underlying infrastructure, hypervisor), while the customer is responsible for security *in* the cloud (e.g., operating system, applications, data, network configurations within the VM). Therefore, patching the operating system of a deployed VM is unequivocally a customer responsibility. This aligns with the principle that the customer has control over the virtualized environment and its contents. The other options represent responsibilities that typically fall under the CSP’s purview in an IaaS model, such as managing the physical security of data centers, ensuring the integrity of the hypervisor, or providing network connectivity to the cloud infrastructure.

The scenario describes a cloud service provider (CSP) that has been notified of a data breach impacting customer data stored within its Infrastructure as a Service (IaaS) offering. The CSP is obligated under ISO 27017:2015 to manage security incidents and to ensure that customers are informed appropriately. Specifically, Clause 6.1.3, “Information security incident management,” mandates that the organization shall ensure that information security incidents are managed in accordance with documented procedures. This includes assessing the impact and severity of incidents and communicating them to relevant parties. Furthermore, Clause 5.3.3, “Information security for use of cloud services,” places a responsibility on the CSP to inform customers of significant changes to the cloud services that may affect their ability to meet their own information security responsibilities. A data breach directly impacts the customer’s ability to meet their security responsibilities, particularly concerning the confidentiality and integrity of their data. Therefore, the CSP must proactively communicate the nature, scope, and potential impact of the breach to affected customers. This communication should enable customers to take necessary actions, such as notifying their own stakeholders or regulatory bodies, and to assess the extent of their own potential liabilities. The absence of timely and transparent communication would be a failure to meet the obligations outlined in the standard for managing cloud security incidents and for supporting customer responsibilities.