The core of this question revolves around the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017:2015. When a cloud service provider (CSP) offers Infrastructure as a Service (IaaS), the responsibility for securing the operating system, middleware, and applications typically rests with the customer. ISO 27017:2015, in its guidance on cloud-specific security controls, emphasizes that while the CSP is responsible for the security *of* the cloud infrastructure (e.g., physical security of data centers, network infrastructure), the customer is responsible for security *in* the cloud. This includes configuring and managing the security of virtual machines, including their patching and vulnerability management. Therefore, in an IaaS model, the customer is directly accountable for ensuring that the operating system deployed on their virtual server is regularly updated and free from known vulnerabilities, a critical aspect of vulnerability management and secure configuration. The CSP’s role is to provide a secure underlying infrastructure, but not to manage the customer’s deployed operating systems.

The scenario describes a cloud service provider (CSP) that has been identified as a customer in the context of ISO 27017:2015. The CSP is responsible for implementing security controls for the cloud services it offers. The question asks about the primary responsibility of the CSP concerning the shared responsibility model in this context. ISO 27017:2015 emphasizes that the CSP is responsible for the security *of* the cloud, meaning the underlying infrastructure, platform, and the security of the services themselves. This includes physical security of data centers, network security, hypervisor security, and the security of the management interfaces. The customer, on the other hand, is responsible for security *in* the cloud, which involves configuring their virtual machines, applications, data, and access controls. Therefore, the CSP’s fundamental obligation is to ensure the security of the cloud environment that it manages and provides to its customers. This aligns with the core principles of the shared responsibility model as defined within the standard, ensuring that the CSP addresses its part of the security assurance.

The core of ISO 27017:2015 lies in defining the responsibilities of cloud service providers (CSP) and cloud service customers (CSC) concerning information security controls in a cloud environment. Clause 5.2.1, “Roles and responsibilities,” specifically addresses this. When a CSP offers a service that relies on a specific control implemented by the CSP, and this control is also a requirement for the CSC (e.g., a control related to the security of the underlying cloud infrastructure that the CSC cannot directly manage), the responsibility for ensuring the effectiveness of that control typically rests with the CSP. However, the CSC still has a responsibility to ensure that the *overall* security posture, including the use of the CSP’s services, meets their own organizational requirements and any applicable legal or regulatory obligations. This involves understanding the shared responsibility model and verifying that the CSP’s controls, as documented and assured, are sufficient for their needs. Therefore, the CSC’s responsibility is to ensure that the CSP’s provided security controls, which are foundational to the service, are adequate for their specific context and risk appetite, even if the direct implementation and operation of those controls are outside the CSC’s purview. This is distinct from the CSC directly implementing controls that are within their scope of management.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015 and how it applies to the specific scenario of data breach notification. In a cloud computing environment, the responsibility for security controls is divided between the Cloud Service Provider (CSP) and the Cloud Service Customer (CSC). ISO 27017:2015, specifically within the context of Annex A controls and their implementation guidance, emphasizes that the CSC retains ultimate responsibility for the data it processes and stores.

When a data breach occurs, the CSC is typically responsible for notifying affected individuals and relevant authorities, as mandated by various data protection regulations like GDPR or CCPA. While the CSP has a responsibility to inform the CSC of security incidents that could impact the CSC’s data or services (as per control A.18.1.4, “Notification of breaches”), the proactive and comprehensive communication of the breach to external parties, including data subjects and supervisory authorities, falls under the CSC’s purview. This is because the CSC is the data controller or processor in most scenarios and possesses the direct relationship with the data subjects. The CSP’s role is to provide the necessary information and support to enable the CSC to fulfill its obligations. Therefore, the primary responsibility for initiating and managing the external notification process rests with the Cloud Service Customer.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015, specifically concerning the implementation of security controls for data processed in a cloud environment. When a cloud service provider (CSP) offers Infrastructure as a Service (IaaS), the CSP is responsible for the security *of* the cloud, which includes the physical infrastructure, networking, and hypervisor. The customer, as the cloud service customer (CSC), is responsible for security *in* the cloud. This encompasses the operating system, middleware, applications, and data.

In the scenario presented, the CSP has implemented robust network segmentation and access controls at the infrastructure level. However, the customer is responsible for configuring and managing the security of the virtual machines they deploy, including the operating systems, patch management, and the security of the applications running on those VMs. Therefore, the vulnerability arising from an unpatched operating system on a customer-deployed VM falls squarely within the CSC’s domain of responsibility. The CSP’s adherence to ISO 27017:2015 would involve providing clear documentation of their responsibilities and the shared responsibility model, enabling the CSC to fulfill their obligations. The question tests the nuanced understanding of where the boundary of responsibility lies for specific security controls in an IaaS model, as guided by the standard.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017 and how it applies to specific cloud security controls, particularly in the context of data deletion and the customer’s responsibility for data residing in the cloud. ISO 27017:2015, Clause 6.3.1, “Customer’s responsibility for data deletion,” explicitly states that the customer is responsible for the deletion of data. This responsibility extends to ensuring that data is securely and permanently removed from the cloud service when it is no longer needed or when the contract terminates. The cloud service provider (CSP) has responsibilities related to the infrastructure and the services they offer, but the ultimate control and decision-making regarding data content and its lifecycle management rest with the customer. Therefore, when a customer requests data deletion, the CSP’s role is to facilitate this process through their provided mechanisms, but the customer must verify the effectiveness of this deletion. This aligns with the principle that the customer retains ownership and accountability for their data. The scenario highlights a common challenge where the customer needs to confirm that data is truly gone, not just marked for deletion or still accessible through residual data. This requires the customer to implement their own verification procedures, which might involve auditing logs provided by the CSP or, in highly sensitive cases, requesting cryptographic proof of deletion if the CSP offers such a service. The emphasis is on the customer’s proactive role in ensuring data disposition aligns with their security policies and regulatory requirements, such as GDPR or CCPA, which mandate the right to erasure.

The scenario describes a cloud service provider (CSP) that has undergone a significant security incident involving a data breach affecting multiple customer tenants. The CSP is obligated under ISO 27017:2015, particularly within the context of clause 6.3.1 (Information security incident management), to effectively manage and respond to such events. A critical aspect of this management, as stipulated by the standard, involves clear communication and collaboration with affected customers. The CSP must provide timely and accurate information regarding the nature of the incident, the scope of the impact, the measures being taken to contain and remediate it, and any actions customers may need to perform. This aligns with the shared responsibility model inherent in cloud computing, where the CSP has responsibilities for the security *of* the cloud, and customers have responsibilities for security *in* the cloud. Therefore, the most appropriate action for the CSP, in line with ISO 27017:2015 principles, is to proactively inform all affected customers about the breach, detailing the impact and the remediation steps, thereby fostering transparency and enabling customers to fulfill their own security obligations. This proactive communication is a cornerstone of effective incident response in a cloud environment, ensuring that all parties are aware and can take necessary actions.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017 and its implications for a cloud service provider (CSP) when a customer experiences a data breach originating from a misconfigured customer-managed virtual machine. ISO 27017:2015, specifically in Clause 5.1.1 (Roles and responsibilities), emphasizes the need for clear definition and communication of responsibilities between the CSP and the customer. While the CSP is responsible for the security *of* the cloud, the customer is responsible for security *in* the cloud. A misconfigured virtual machine, such as an improperly secured administrative interface or an open, unencrypted data storage bucket, falls squarely within the customer’s domain of responsibility. Therefore, the CSP’s obligation is to provide the secure infrastructure and services, and to have mechanisms in place to detect and report potential security incidents. However, the direct cause of the breach being a customer-managed configuration means the remediation and direct accountability for the breach’s impact rest with the customer. The CSP’s role would be to cooperate with the customer’s investigation and provide any relevant logs or access controls that were within their purview. The question tests the nuanced understanding of where the boundary of responsibility lies for a specific type of security incident in a cloud environment governed by ISO 27017. The correct approach is to identify the control that was directly compromised due to customer action or inaction, and attribute the primary responsibility accordingly, while acknowledging the CSP’s overarching security obligations.

The core of this question lies in understanding the shared responsibility model within cloud computing, specifically as it pertains 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 ultimate accountability for the security of their data and the configuration of the services they consume. ISO 27017 emphasizes that the CSC must implement controls relevant to their specific use of cloud services, including data protection, access management, and vulnerability management within their deployed environments. The scenario describes a situation where a CSC has deployed a custom application in the cloud and is experiencing a data breach originating from a vulnerability within that application. This vulnerability is not a flaw in the underlying cloud infrastructure provided by the CSP, but rather in the code developed and deployed by the CSC. Therefore, the responsibility for identifying, assessing, and remediating this application-level vulnerability rests squarely with the CSC. The CSP’s responsibility would extend to the security of the cloud infrastructure itself, not the specific application code developed by the customer. Consequently, the most appropriate action for the CSC is to immediately patch the application to address the identified vulnerability. This aligns with the CSC’s obligation to manage risks associated with their data and applications in the cloud environment, as mandated by the shared responsibility model and the principles of ISO 27017.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015, specifically concerning the management of cryptographic keys in a cloud environment. When a customer utilizes a cloud service that employs encryption for data at rest, the responsibility for managing those cryptographic keys is a critical point of delineation. ISO 27017:2015, in conjunction with Annex A controls, emphasizes that while the cloud service provider (CSP) may offer encryption services and manage the underlying infrastructure that supports key management, the ultimate control and responsibility for the keys themselves, particularly those protecting the customer’s data, typically rests with the customer. This is because the customer is the entity that defines the data’s sensitivity, the encryption algorithms, and the access policies. The CSP’s role is to provide a secure environment and the mechanisms for key management, but the strategic decisions and operational oversight of the keys that secure the customer’s information remain a customer responsibility. Therefore, the customer must implement controls to ensure the confidentiality, integrity, and availability of their cryptographic keys, which includes secure generation, storage, distribution, and destruction. This aligns with the principle that the party responsible for the data’s protection is also responsible for the keys that protect it.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their Infrastructure as a Service (IaaS) offering. ISO 27017:2015, specifically Clause 6.2.3 (Information security incident management), mandates that organizations establish and maintain an information security incident management process. This process should include responsibilities for reporting, assessing, and responding to security incidents. Furthermore, Clause 6.2.4 (Information security incident response) requires the CSP to have a documented incident response plan that outlines procedures for handling incidents, including communication with affected parties. Given that the breach involved customer data, the CSP has a contractual and ethical obligation to inform its customers about the incident, its potential impact, and the steps being taken to mitigate further risks. This aligns with the principles of transparency and accountability inherent in cloud security best practices and the specific requirements of ISO 27017 for managing incidents and communicating with customers. The CSP’s proactive communication, detailing the nature of the breach, the types of data compromised, and the remediation efforts, is a direct application of these clauses.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their Infrastructure as a Service (IaaS) offering. ISO 27017:2015, specifically Clause 6.2.2 (Information security incident management), mandates that cloud service providers must establish and maintain a process for managing information security incidents, including their reporting. Furthermore, Clause 6.2.3 (Information security incident response) requires the CSP to have a documented incident response plan that includes procedures for assessing and responding to incidents. Given that the breach involved customer data, the CSP has a contractual and ethical obligation to inform its customers. The most appropriate action, aligning with the principles of transparency and accountability inherent in ISO 27017, is to notify affected customers promptly about the nature and scope of the breach, the potential impact, and the steps being taken to mitigate further risks. This notification process should be part of the CSP’s established incident response procedures.

The core of ISO 27017:2015 is to provide guidance on information security controls for cloud services. When a cloud service customer (CSC) is migrating sensitive data, the shared responsibility model is paramount. The standard emphasizes that while the cloud service provider (CSP) is responsible for the security *of* the cloud, the CSC is responsible for security *in* the cloud. This includes ensuring that the data classification and handling policies of the CSC are adequately supported by the CSP’s infrastructure and services, and that appropriate controls are implemented by the CSC to protect the data during transit and at rest. Specifically, the standard addresses the need for the CSC to understand the CSP’s security capabilities and to implement their own security measures that align with their risk assessment and regulatory requirements. The scenario describes a migration of sensitive data, which necessitates a thorough review of the CSP’s security posture and the CSC’s own controls. The most critical aspect for the CSC in this context is to verify that the CSP’s security controls and contractual agreements adequately address the CSC’s specific security requirements for the sensitive data being migrated, ensuring compliance with relevant regulations like GDPR or HIPAA, and that the CSC’s own implementation of security measures in the cloud environment is robust. This involves understanding the shared responsibility for specific controls and ensuring no gaps exist.

The core of this question lies in understanding the shared responsibility model as delineated by ISO 27017:2015, specifically concerning the customer’s obligations when utilizing Infrastructure as a Service (IaaS). In an IaaS model, the cloud service provider (CSP) is responsible for the security *of* the cloud infrastructure (e.g., physical security of data centers, network infrastructure, hypervisors). The customer, however, is responsible for security *in* the cloud. This includes the operating systems, applications, data, and identity and access management within their deployed virtual machines and services. Therefore, when a customer deploys a new virtual server instance in an IaaS environment, the responsibility for configuring and maintaining the security of that operating system, including patching and vulnerability management, rests with the customer. The CSP’s responsibility is limited to ensuring the underlying infrastructure supporting that instance is secure. The question probes the nuanced understanding of where the customer’s security obligations begin in a cloud context, particularly in IaaS, which is a fundamental concept for a Cloud Security Lead Implementer.

The question revolves around the shared responsibility model in cloud computing, specifically as it pertains to ISO 27017:2015. The standard emphasizes that both the cloud service provider (CSP) and the cloud service customer (CSC) have distinct but overlapping responsibilities for security. When a CSC utilizes a Platform as a Service (PaaS) offering, the CSP is typically responsible for the security *of* the cloud infrastructure, including the underlying hardware, networking, and virtualization layers, as well as the operating system and middleware. The CSC, however, is responsible for the security *in* the cloud, which includes their applications, data, identity and access management configurations, and any operating system patches or configurations not managed by the CSP.

In the given scenario, the CSC has deployed a custom application on a PaaS. The vulnerability lies within the application’s code, specifically in how it handles user input, leading to a potential injection attack. This type of vulnerability is squarely within the CSC’s domain of responsibility, as they developed and deployed the application. The CSP’s responsibility for PaaS generally extends to the platform’s integrity, not the specific security flaws within customer-developed applications running on that platform. Therefore, the CSC is accountable for remediating this application-level vulnerability. The explanation of the correct approach involves the CSC performing a thorough code review, implementing secure coding practices, and deploying a patched version of the application. This aligns with the CSC’s obligation to secure their data and applications within the cloud environment, as stipulated by ISO 27017:2015.

The core of this question lies in understanding the shared responsibility model within cloud computing, specifically as it pertains to ISO 27017:2015. When a cloud service customer (CSC) utilizes a cloud service, certain security controls are the responsibility of the cloud service provider (CSP), while others remain with the CSC. ISO 27017:2015 provides guidance on these responsibilities. Specifically, Annex A.5.1.1, “Information security policy,” and Annex A.5.1.2, “Information security roles and responsibilities,” are crucial. The standard emphasizes that the CSC is responsible for defining and implementing its own information security policies and assigning roles and responsibilities for information security within its organization, even when using cloud services. This includes ensuring that personnel are aware of their responsibilities concerning the cloud environment. The CSP is responsible for the security *of* the cloud infrastructure, but the CSC is responsible for security *in* the cloud, which encompasses its own policies, procedures, and personnel management related to cloud usage. Therefore, the CSC must ensure its internal policies and procedures adequately address the use of cloud services and the security responsibilities it retains.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their Infrastructure as a Service (IaaS) environment. The CSP is operating under the framework of ISO 27017:2015, which mandates specific responsibilities for both CSPs and cloud service customers. In this situation, the CSP has a contractual obligation to inform the affected customers about the breach, as per clause 5.3.2.1 of ISO 27017:2015, which deals with “Information security incident management” and emphasizes timely notification to relevant parties. Furthermore, the CSP must also consider its responsibilities related to the shared responsibility model inherent in cloud computing. While the customer is responsible for securing their data within the IaaS environment, the CSP is responsible for the security of the underlying infrastructure. A failure to promptly notify customers about a breach impacting their data, even if the root cause is within the customer’s control, represents a failure in incident management and communication, which are core tenets of ISO 27017. The CSP’s obligation extends to providing sufficient information to enable the customer to take appropriate action, which includes understanding the nature and scope of the incident. Therefore, the most appropriate action for the CSP is to provide a comprehensive notification to all affected customers detailing the incident, its potential impact, and any immediate steps being taken. This aligns with the principles of transparency and accountability expected of a cloud service provider adhering to ISO 27017.

The core of ISO 27017:2015 is the mapping of its controls to ISO 27002:2013 and the identification of cloud-specific controls. When a cloud service customer (CSC) needs to implement controls that are the responsibility of the cloud service provider (CSP) as per their agreement, the CSC must ensure that the CSP provides evidence of implementation. This evidence is crucial for the CSC to demonstrate compliance with its own security obligations, especially when those obligations are influenced by regulatory requirements like GDPR or HIPAA, which mandate data protection and accountability. The CSC cannot simply delegate responsibility without verification. Therefore, the CSC should request documented assurance from the CSP regarding the implementation of shared responsibility controls. This assurance might take the form of audit reports, certifications, or specific contractual clauses detailing the CSP’s adherence to the relevant controls. The absence of such evidence means the CSC cannot confidently assert that the required security measures are in place, potentially leading to non-compliance and increased risk.

No calculation is required for this question.

The core of ISO 27017:2015 is to provide guidance on information security controls for cloud services. A critical aspect of this standard is the delineation of responsibilities between the cloud service customer and the cloud service provider. When a cloud service provider offers Infrastructure as a Service (IaaS), the provider is responsible for the security *of* the cloud (i.e., the underlying infrastructure, virtualization layer, and physical security). The customer, conversely, is responsible for security *in* the cloud, which encompasses the operating system, applications, data, and user access management. This division of responsibility is fundamental to establishing an effective cloud security posture and ensuring that all relevant security controls are implemented and maintained by the appropriate party. Misunderstanding this division can lead to security gaps, where critical controls are neither implemented by the provider nor the customer, leaving the cloud environment vulnerable. Therefore, a clear understanding of these shared responsibilities, as outlined in ISO 27017, is paramount for successful cloud security management.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015 and how it applies to the management of cryptographic keys in a cloud environment. Specifically, when a customer (the cloud service customer) utilizes a cloud service that employs encryption for data at rest, the responsibility for managing the encryption keys typically remains with the customer, unless explicitly stated otherwise in the contract or service agreement. ISO 27017:2015, in its guidance on cryptographic controls (specifically referencing Annex A.10.1.2), emphasizes the customer’s role in managing keys for data they control. While the cloud service provider (CSP) might offer encryption services, the ultimate control and management of the keys used to encrypt the customer’s data are usually retained by the customer to ensure data confidentiality and integrity. This allows the customer to maintain sovereignty over their data and manage access to it independently of the CSP’s infrastructure. Therefore, the responsibility for key management, including generation, storage, rotation, and revocation, falls to the customer in this scenario.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their Infrastructure as a Service (IaaS) offering. ISO 27017:2015, specifically in Annex A, clause A.18.1.4, addresses the responsibilities of cloud service customers and cloud service providers regarding the reporting of security incidents. The standard emphasizes that both parties should have defined procedures for reporting security incidents. In this context, the CSP has a direct responsibility to inform its customers about breaches impacting their data, as per the principles of transparency and shared responsibility in cloud security. The prompt highlights that the CSP has not yet notified the affected customers. Therefore, the most appropriate action for the CSP, aligned with ISO 27017:2015, is to promptly inform the affected customers about the security incident and its potential impact. This aligns with the overarching goal of maintaining trust and ensuring that customers can take necessary actions to protect themselves. Other options are less direct or misinterpret the CSP’s primary obligation in this situation. For instance, focusing solely on internal investigation without customer notification delays crucial information. Similarly, waiting for regulatory bodies to mandate notification is reactive and undermines the proactive stance expected of a CSP. Engaging legal counsel is a necessary step, but it should not precede or replace the fundamental obligation to inform affected parties.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their IaaS environment. The CSP is obligated to inform affected customers according to contractual agreements and potentially relevant data protection regulations. ISO 27017:2015, specifically in the context of cloud security responsibilities, emphasizes the importance of communication during security incidents. Clause 5.3.1, “Information security incident management,” and Annex A, specifically A.5.3.1, “Information security incident management,” highlight the need for a defined process for managing information security incidents, which includes communication. Furthermore, the CSP’s role as an IaaS provider means they are responsible for the security *of* the cloud infrastructure, but customers are responsible for security *in* the cloud. However, when a breach originates from the CSP’s infrastructure, they have a direct responsibility to notify their customers about the incident’s impact on their data. This notification should be timely, informative, and aligned with any specific legal or contractual requirements, such as those found in GDPR or similar data protection laws that mandate breach notification. The core principle is transparency and fulfilling the CSP’s duty of care to its customers. Therefore, the most appropriate action is to initiate customer notification, detailing the nature of the breach, the potential impact on their data, and the steps being taken to mitigate the issue and prevent recurrence.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015 and its implications for incident management in a cloud environment. Specifically, it tests the ability to identify which party is primarily accountable for the remediation of a security incident originating from a customer-managed virtual machine within a public cloud Infrastructure as a Service (IaaS) offering.

In an IaaS model, the cloud service provider (CSP) is responsible for the security *of* the cloud infrastructure (e.g., physical security of data centers, network infrastructure, hypervisor). The customer, however, is responsible for security *in* the cloud, which includes the operating system, applications, data, and configurations of their virtual machines.

When a security incident, such as unauthorized access, occurs due to a vulnerability or misconfiguration within the customer’s virtual machine (e.g., an unpatched operating system or a weak access control list on a storage volume attached to the VM), the responsibility for investigating, containing, eradicating, and recovering from that incident rests with the customer. This is because the root cause is within the customer’s domain of control. The CSP’s role would be to support the customer by providing logs or access to the underlying infrastructure if required and if the incident impacts the CSP’s responsibilities, but the primary remediation actions for the VM itself are customer-driven.

Therefore, the customer is accountable for the remediation actions.

The core of ISO 27017:2015 is to provide guidance on information security controls for cloud services, building upon ISO 27002. When a cloud service customer (CSC) is migrating sensitive data to a cloud service provider (CSP), the responsibility for implementing specific security controls is a shared one, defined by the cloud service agreement (CSA). ISO 27017 emphasizes that while the CSP is responsible for the security *of* the cloud infrastructure, the CSC retains responsibility for security *in* the cloud, particularly concerning their data and applications. Clause 6.1.2 of ISO 27017, “Responsibilities for cloud services,” and Annex A, which maps controls to ISO 27002 and adds cloud-specific controls, are crucial here. Specifically, controls related to data encryption, access management, and vulnerability management for the CSC’s deployed services are paramount. The CSC must ensure that their chosen encryption methods meet their data protection requirements and that access to their cloud-based data is strictly controlled through robust identity and access management (IAM) policies. Furthermore, the CSC is accountable for patching and securing the operating systems and applications they deploy within the cloud environment, even if the underlying infrastructure is managed by the CSP. Therefore, the CSC’s primary focus should be on securing their data and applications within the cloud environment, which includes implementing appropriate encryption and access controls for their data assets.

The core of this question lies in understanding the shared responsibility model as defined by ISO 27017:2015, specifically concerning the customer’s obligations when utilizing Infrastructure as a Service (IaaS). In an IaaS model, the cloud service provider (CSP) is responsible for the security *of* the cloud, which includes the underlying infrastructure, virtualization layer, and physical security. The customer, however, is responsible for security *in* the cloud. This encompasses the operating system, middleware, applications, and data. When a customer deploys a custom application on an IaaS platform, they are directly responsible for securing the application’s code, its dependencies, and the configuration of the operating system and network services that host it. This includes vulnerability management within the deployed OS and ensuring the application itself is free from common web vulnerabilities like SQL injection or cross-site scripting. The CSP’s responsibility ends at providing a secure and functional IaaS environment. Therefore, the customer must implement security controls for their specific application and its operating environment.

The scenario describes a cloud service provider (CSP) that has been subject to a data breach affecting customer data stored in their IaaS environment. The CSP is obligated to notify affected customers under various data protection regulations, such as the GDPR (General Data Protection Regulation) if EU citizens’ data is involved, or similar state-level breach notification laws in the US. ISO 27017:2015, specifically in clause 6.1.3 (Information security incident management), mandates that organizations establish and maintain an information security incident management process. This process should include procedures for assessing and responding to information security incidents, which encompasses timely and appropriate communication with relevant stakeholders, including affected customers. The CSP’s contractual obligations with its customers, often detailed in Service Level Agreements (SLAs) or specific cloud service agreements, will also dictate the notification requirements, including timelines and content. Therefore, the most critical immediate action for the CSP, beyond containment and eradication of the breach, is to initiate the customer notification process as per regulatory and contractual mandates. This proactive communication is essential for maintaining trust, mitigating reputational damage, and fulfilling legal responsibilities. The other options, while potentially part of a broader response, are not the *most* critical immediate action for the CSP in this specific context of customer data compromise. Conducting a full forensic analysis is important but can commence concurrently with or immediately after initiating notification. Reviewing the CSP’s own internal access logs is a component of the forensic analysis, not the primary customer-facing action. Developing a long-term remediation strategy is a subsequent step after understanding the root cause and impact.

The scenario describes a cloud service provider (CSP) that has experienced a data breach affecting customer data stored in their Infrastructure as a Service (IaaS) offering. The breach was caused by an unpatched vulnerability in the hypervisor layer, which is a component managed by the CSP. ISO 27017:2015, specifically Clause 6.2.1 (Information security roles and responsibilities), mandates that responsibilities for information security in a cloud computing environment must be clearly defined and communicated. In an IaaS model, the CSP is responsible for the security *of* the cloud infrastructure, including the underlying hardware, virtualization layer (hypervisor), and network infrastructure. The customer, on the other hand, is responsible for security *in* the cloud, which includes the operating system, applications, and data they deploy. Since the breach originated from a vulnerability in the hypervisor, a component under the CSP’s direct control and management, the CSP has failed to meet its contractual and security obligations as per ISO 27017’s principles for shared responsibility. The CSP’s responsibility extends to ensuring the security of the foundational elements upon which the customer builds their services. Therefore, the CSP is primarily accountable for the incident and the subsequent remediation and notification efforts. The question asks for the most appropriate initial action by the CSP in this situation, considering their responsibilities. The most critical first step is to contain the breach and prevent further unauthorized access, which aligns with the principles of incident management outlined in ISO 27001 (which ISO 27017 builds upon) and general cybersecurity best practices. This includes isolating affected systems and investigating the root cause.

The core of ISO 27017:2015, particularly in relation to customer responsibilities in a cloud environment, centers on the shared responsibility model. When a cloud service customer (CSC) utilizes Infrastructure as a Service (IaaS), the cloud service provider (CSP) is responsible for the security *of* the cloud, encompassing the physical infrastructure, network, and hypervisor. The CSC, however, is responsible for security *in* the cloud. This includes the operating system, middleware, applications, and data. Specifically, ISO 27017:2015 clause 6.3.1, “Responsibilities of the cloud service customer,” outlines the CSC’s obligations. Among these is the responsibility to manage and secure the virtual machines, including their operating systems and applications, and to ensure that any data stored or processed within these virtual machines is adequately protected. This involves implementing appropriate access controls, encryption, and vulnerability management for the resources they deploy and manage. Therefore, the most accurate statement reflects the CSC’s duty to secure the operating system and applications deployed on IaaS.

The core of ISO 27017:2015 revolves around the shared responsibility model in cloud computing and the specific controls applicable to cloud service customers (CSCs) and cloud service providers (CSPs). When a CSC migrates sensitive data to a CSP, the CSC retains ultimate accountability for the data’s security, even though the CSP manages the underlying infrastructure. ISO 27017:2015 Clause 5.3.1, “Responsibilities for cloud services,” emphasizes the need for clear documentation of these responsibilities. Specifically, it mandates that the CSC and CSP jointly define and document responsibilities for implementing security controls. This includes identifying which controls are the sole responsibility of the CSC, which are the sole responsibility of the CSP, and which are shared. The scenario describes a situation where the CSC has outsourced the management of its virtual machines, including patching and vulnerability management, to the CSP. According to ISO 27017:2015, the CSC must ensure that these outsourced responsibilities are clearly defined in the service agreement and that the CSP’s implementation of these controls meets the CSC’s security requirements. The CSC cannot abdicate its responsibility by simply outsourcing; it must verify and oversee the CSP’s performance. Therefore, the most appropriate action for the CSC is to formally document the agreed-upon responsibilities for virtual machine security, including patching and vulnerability management, within the cloud service agreement, ensuring alignment with ISO 27001 Annex A controls and the specific requirements of ISO 27017. This documentation serves as the basis for accountability and ongoing assurance.

The scenario describes a cloud customer, “Aether Dynamics,” who has identified a potential security gap in their cloud service provider’s (CSP) incident response capabilities concerning data breaches originating from shared infrastructure. ISO 27017:2015, specifically Clause 6.1.3 (Information security incident management), mandates that both the cloud service customer and the CSP establish and maintain a set of information security incident management procedures. For a cloud customer, this involves defining their responsibilities in reporting incidents to the CSP and cooperating with the CSP’s incident response processes.

The core of the issue lies in Aether Dynamics’ need to ensure their contractual agreements with the CSP adequately cover the CSP’s obligations during a shared infrastructure data breach. This directly relates to the customer’s responsibility to understand and influence the CSP’s incident handling, particularly when the breach impacts the customer’s data. The standard emphasizes clear roles and responsibilities, communication channels, and cooperation during incidents. Therefore, the most effective action for Aether Dynamics is to review and potentially amend their cloud service agreement to explicitly define the CSP’s responsibilities and the expected response timeline for breaches affecting shared resources. This ensures alignment with the principles of shared responsibility and the requirements for effective incident management as outlined in ISO 27017.