What is the Shared Responsibility Model, and Why Does It Need Modernization?
The shared responsibility model is a foundational framework that delineates security responsibilities between cloud service providers (CSPs) and their customers. Under this model, CSPs take charge of securing the cloud infrastructure, while customers are responsible for safeguarding their own data, applications, and configurations. This division is essential, yet many organizations misunderstand the extent of their responsibilities, leading to significant security gaps.
CSPs vs. Customers: Understanding Responsibilities
CSPs manage a range of security measures related to the physical data centers, network hardware, and core services, including operating system patching and availability guarantees. For instance, Amazon Web Services (AWS) is responsible for the security of its physical data centers and service reliability. However, AWS customers must actively manage access controls, configure permissions, encrypt data, and monitor resource usage continuously. The assumption that CSPs oversee all security aspects can result in dangerously misleading insights, making it imperative to clarify roles and responsibilities as cloud environments evolve in complexity.
Why the Old Shared Responsibility Model No Longer Fits Modern Cloud Environments
The initial shared responsibility model has not kept pace with the rapidly changing cloud landscape. With distributed architectures, multi-cloud environments, and the emergence of serverless computing, the responsibilities have become increasingly blurred. The advent of Artificial Intelligence (AI) and ephemeral infrastructure presents new challenges that the traditional model fails to address.
For example, in the context of AI, workloads require accountability that extends from data lineage and model integrity to training security and inference protection—dimensions that traditional Infrastructure as a Service (IaaS) models did not factor in. The responsibilities that fall on customers can shift drastically depending on the service type and deployment style, leading to security gaps when security teams rely on outdated models.
Understanding the Goal of Modernization: Clarity, Not Complexity
Modernizing the shared responsibility model aims for clarity in roles and ownership, rather than adding layers of complexity. The goal is to empower teams to understand what they own, how they should secure it, and how various teams can collaborate effectively.
A modernized framework democratizes security across different groups within an organization by emphasizing accurate role mapping and continuous validation. This approach helps minimize risk while accelerating innovation, allowing teams to understand their specific responsibilities within cloud environments.
How Shared Responsibility Varies by Service Type
The boundaries of the shared responsibility model shift according to the type of cloud service being used:
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Infrastructure as a Service (IaaS): In this model, customers shoulder the broadest array of responsibilities. While the CSP secures the physical infrastructure, customers must manage the operating system, middleware, applications, configurations, user access, and data. For instance, AWS EC2 clients must handle firewall configurations, patch management, and identity and access management (IAM) policies even while Amazon secures the hypervisor and ensures uptime.
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Platform as a Service (PaaS): In PaaS environments, more responsibility aligns with the CSP, encompassing infrastructure and operating system security. Customers concentrate on application code, data handling, and access controls. A prime example is Google App Engine, where developers can deploy code without engaging with the underlying infrastructure directly.
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Software as a Service (SaaS): Here, customers depend heavily on the CSP for security across the application stack. The provider takes care of application, infrastructure, availability, and performance security, while customers must focus on user management and data protection within the app. For example, with Microsoft 365, customers must configure access permissions while the provider ensures uptime and data security.
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Function as a Service (FaaS): In serverless computing models like AWS Lambda, the customer mainly focuses on code and application logic, leaving infrastructure management to the CSP. Despite the abstraction, customers must secure environment variables, roles, and validation processes to ensure that their code executes securely.
Customers’ Cloud Security Responsibilities Today
With cloud customers actively managing their security, it’s essential to grasp the key areas where they hold responsibility. These responsibilities can be distilled into four core areas:
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Data Protection and Encryption: Customers must manage data confidentiality, integrity, and availability by monitoring encryption in transit and at rest. Misconfigurations in encryption policies are a leading cause of data breaches, making careful management of backup processes vital.
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Identity and Access Management: Controlling access across cloud services is crucial. Customers should implement least-privilege access policies, use temporary credentials rather than long-lived access keys, and employ multi-factor authentication (MFA) to reduce unauthorized access risks.
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Configuration and Posture Management: Continuous monitoring for configuration drift and regularly validating cloud posture are crucial in preventing misconfigurations—a frequent source of security vulnerabilities. Organizations must ensure that all workloads align with their internal security standards.
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Application and Workload Security: Customers are responsible for securing their applications and workloads. This includes adhering to secure coding practices, conducting regular vulnerability assessments, and integrating automated security tests into CI/CD pipelines.
What Are Cloud Service Providers’ Security Responsibilities?
CSPs have specific responsibilities they need to uphold to enable customers to build secure systems:
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Physical and Infrastructure Security: They operate secure data centers, manage physical access controls, and safeguard servers and virtualization layers.
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Core Network and Availability: Providers secure network infrastructure, ensuring that they meet uptime commitments and have systems in place for DDoS mitigation and threat detection.
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Shared Services and Compliance: CSPs support customers in achieving compliance by undergoing third-party audits and providing necessary compliance artifacts.
What CSPs Don’t Cover
CSPs do not assume security tasks that fall to customers, like managing IAM policies, application permissions, or controlling data exposure. By not securing operating systems, APIs, or in-app data flows, CSPs intentionally shift those responsibilities to the customer.
Where Responsibilities Overlap, and How to Avoid Ambiguity
Some responsibilities lie in a gray area where both CSPs and customers influence the security outcome. Consequently, organizations must prioritize clear communication and documented ownership to prevent confusion and ambiguity.
Biggest Challenges Teams Face with the Shared Responsibility Model
Even with well-defined roles, organizations often struggle to operationalize the shared responsibility model effectively. Challenges include:
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Ambiguity and Assumption Risk: Teams may mistakenly believe that using cloud-native services automatically ensures security, exposing them to risks such as misconfigured Amazon S3 settings or unencrypted data.
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Responsibility Fatigue: Rapidly changing cloud environments complicate security processes. Without automation, security teams face burnout and can’t consistently meet their responsibilities.
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Compliance Confusion: Compliance frameworks don’t always define specific customer responsibilities, leading to misunderstandings about necessary controls.
How Wiz Simplifies the Shared Responsibility Model for Modern Cloud Teams
Wiz was designed to enhance visibility and clarity around the shared responsibility model. With capabilities that allow teams to gain unified views of risks across multi-cloud environments, Wiz helps organizations minimize ambiguity and streamline security processes efficiently.
By understanding the specific functionalities offered by Wiz, organizations can better fulfill their responsibilities and improve remediation times—even in complex cloud infrastructures—thereby securing their environments more effectively.