Cloud shared responsibility governance

Cloud programs fail audits and drive incidents for a simple reason: teams assume “the cloud provider handles security,” while providers assume “the customer configures and operates security.” The cloud shared responsibility governance requirement closes that gap by forcing a documented, owned, and maintained split of responsibilities between cloud providers and customers ¹.

For a Compliance Officer, CCO, or GRC lead, the practical goal is not to write a policy. It’s to create a governance mechanism that survives real operations: new cloud accounts, new managed services, platform changes, M&A migrations, and developer self-service. Auditors and assessors will look for two things: (1) a clear responsibility definition that is specific enough to drive action, and (2) evidence that the organization uses it to allocate ownership, implement controls, and manage gaps over time.

This page gives you requirement-level implementation guidance: who must comply, how to build a shared responsibility matrix that stands up in an ISO 27017-aligned assessment, what artifacts to retain, and a practical execution plan you can start this week.

Regulatory text

Provided excerpt (non-licensed summary): “Baseline implementation-intent summary derived from publicly available framework overviews; licensed standard text is not reproduced in this record.” The implementation intent summary for this requirement is: “Define security responsibilities between cloud providers and customers.” ¹

What the operator must do:
You need a governed method to define, communicate, and maintain who is responsible for each relevant security activity and control in your cloud environment, distinguishing what the cloud provider does versus what you must configure, operate, and monitor. This is not satisfied by referencing a provider’s generic shared responsibility model; you must translate it into your environment, your services, and your control set ¹.

Plain-English interpretation (what this requirement really demands)

You are accountable for security outcomes, even when infrastructure is outsourced. Cloud shared responsibility governance means you:

1. Make responsibilities explicit (no assumptions).
2. Assign accountable owners inside your organization (by role, not a named person).
3. Confirm the provider responsibilities through contractual terms and provider documentation.
4. Operate the split through onboarding, architecture reviews, and change management so the matrix stays accurate.

A good test: if an engineer asks, “Who patches this component?” or “Who configures logging for this service?” you can answer from a controlled document and point to the owner and the enforcement mechanism.

Who it applies to

Entity types:

• Cloud customers running workloads, data, identities, and applications in cloud services (IaaS, PaaS, SaaS).
• Cloud providers delivering cloud services and defining their responsibilities to customers.
  (ISO 27017 addresses both perspectives; most compliance teams implementing this requirement are cloud customers) ¹

Operational contexts where it matters most:

• Multi-account / multi-subscription cloud estates with delegated administration.
• Heavy use of managed services (PaaS, serverless, managed databases), where the boundary is less obvious than IaaS.
• Regulated data processing, where evidence of control operation is required.
• Third-party delivered cloud layers (MSPs, SaaS on top of IaaS), where responsibility becomes “stacked.”

What you actually need to do (step-by-step)

Step 1: Define scope and service taxonomy

Create a list of:

• Cloud providers in scope (AWS/Azure/GCP, plus SaaS platforms that host sensitive data).
• Cloud service types used (compute, storage, database, container platform, CI/CD, IAM, key management, logging/SIEM integrations).
• Data classes and environments (prod, non-prod) that drive different control expectations.

Output: Cloud services inventory for governance purposes (not a CMDB replacement).

Step 2: Build a shared responsibility matrix that is service-specific

Create a matrix with rows for security domains and columns for:

• Cloud provider responsibility (what the provider does)
• Customer responsibility (what you must do)
• Shared/conditional responsibility (depends on service configuration)
• Accountable owner role (your internal role: Cloud Platform, App Owner, Security Engineering, IAM team, GRC, etc.)
• Evidence pointer (where proof lives: ticketing, config rule, logs, contract clause)

Minimum row set (practical):

• Identity and access management (user lifecycle, MFA, privileged access)
• Logging and monitoring (audit logs, retention, alerting ownership)
• Encryption (at rest, in transit, key ownership, rotation)
• Network security (segmentation, firewall rules, private endpoints)
• Vulnerability and patching (who patches OS/runtime/service)
• Configuration management (baseline, drift detection, IaC standards)
• Backup and recovery (RPO/RTO ownership, testing ownership)
• Incident response (who detects, who escalates to provider, support SLAs)
• Data deletion and tenant isolation (especially for SaaS)
• Compliance reporting (SOC reports, penetration testing boundaries)

Tip that prevents “generic matrix” failure: maintain one “core matrix” template, then instantiate it per service family (for example: “Managed database,” “Object storage,” “Kubernetes service,” “SaaS HR system”). Auditors will accept a structured approach if each instantiated matrix is complete for services in use.

Step 3: Map the matrix to your control framework and procedures

For each customer responsibility, map to:

• The internal control (policy/control statement)
• The operational procedure (runbook, standard)
• The technical mechanism (cloud config, guardrail, monitoring rule)
• The verification method (continuous control monitoring, internal audit test step)

Output: A crosswalk that proves the matrix drives control design and operation, rather than sitting in a binder.

Step 4: Contract and third-party alignment

Confirm that provider responsibilities are supported by:

• Contract terms (security obligations, incident notification, support and escalation, audit/support of assurance reports)
• Provider documentation and assurance artifacts that your third-party risk program reviews

Where the provider disclaims responsibility, your matrix must show the customer-owned compensating activity.

Output: Contract review memo or checklist entries that link to the matrix responsibilities.

Step 5: Operationalize through governance checkpoints

Embed the matrix into:

• Cloud account/subscription onboarding (no production go-live until responsibilities and owners are confirmed)
• Architecture review (new service adoption must instantiate a matrix)
• Change management (provider feature changes and your major changes trigger responsibility review)
• Incident response (runbooks reference the provider/customer handoff points)

Output: Documented process steps and workflow evidence (tickets, approvals, change records).

Step 6: Review cadence and exception handling

Set a review cadence tied to:

• New service onboarding
• Material architecture change
• Contract renewal
• Major provider change notices (where applicable)

Track exceptions where responsibilities cannot be met immediately. Require a time-bound remediation plan, compensating controls, and formal risk acceptance where necessary.

Output: Review records, exception register entries, risk acceptances.

Required evidence and artifacts to retain

Auditors will ask for proof of definition, ownership, and operation. Maintain:

• Shared responsibility matrix (version-controlled, with service coverage noted)
• RACI or accountability assignments by role/team
• Control crosswalk (matrix responsibility → internal control → procedure → evidence)
• Cloud onboarding checklist showing the matrix step is required
• Architecture review records for new cloud services referencing the matrix
• Change management records showing responsibility updates after material changes
• Third-party due diligence artifacts used to validate provider responsibilities (for example, security addendum review notes)
• Exception register / risk acceptances for gaps in customer responsibilities
• Training/communications artifacts for cloud/platform teams (briefing deck, internal wiki page, acknowledgments)

Keep artifacts in a system that preserves timestamps and approver identity (GRC tool, controlled wiki with approvals, ticketing system).

Common exam/audit questions and hangups

Expect these:

1. “Show me your shared responsibility model for the cloud.” They mean your model, not the provider’s marketing page.
2. “Which team owns logging for managed services?” Vague answers (“security owns it”) fail without a named role and procedure.
3. “How do you ensure the matrix stays current?” They want change triggers and review evidence.
4. “How do contracts reflect responsibilities?” If your matrix says provider notifies you of incidents, but the contract is silent, you have a governance gap.
5. “How do you test that customer responsibilities are performed?” They want operational evidence: config rules, scan results, ticket closure.

Hangup pattern: teams produce a matrix but can’t show it drives real workflows.

Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails	Fix
Using a single generic matrix for “AWS/Azure”	Managed services shift responsibilities by service	Instantiate per service family and require it for new service adoption
Treating provider SOC reports as “provider handles security”	Assurance reports don’t operate your configurations	Map each customer responsibility to your control evidence
No named accountable owner	Work falls between platform, security, and app teams	Assign an accountable role per row; align to org chart
No linkage to contracts	Provider responsibilities may not be enforceable	Tie key responsibilities to contract clauses and renewal reviews
Matrix exists but teams don’t know it	Governance artifact becomes shelfware	Embed into onboarding, architecture review, and IR runbooks

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement. Practically, the risk is operational: shared responsibility confusion creates predictable control gaps (for example, unmonitored logs, misconfigured storage access, unmanaged identities). In regulated environments, those gaps commonly translate into audit findings, delayed certifications, and incident response failures. ISO 27017’s intent is to make the boundary explicit and govern it ¹.

Practical 30/60/90-day execution plan

First 30 days: establish the governance “spine”

• Name an executive owner (security or technology) and an operator (cloud security or GRC).
• Inventory cloud providers and the top services hosting sensitive data.
• Publish a shared responsibility matrix template with mandatory fields: responsibility, owner role, evidence pointer.
• Run two workshops: one with cloud platform/security, one with application owners, to validate boundaries.
• Start a centralized repository (version control or GRC system) and define approval workflow.

Daydream fit (earned): If you already manage third-party due diligence and control evidence in Daydream, store the matrix, crosswalk, and contract review evidence in the same program so audits can trace responsibility to proof without manual hunting.

Next 60 days: operationalize and connect to controls

• Instantiate matrices for each high-risk service family in active use.
• Map each customer responsibility to an internal control and evidence source.
• Update cloud onboarding and architecture review checklists to require a matrix before production use.
• Add an exception workflow: gap, compensating control, owner, remediation plan, risk acceptance path.

Next 90 days: prove it runs and stays current

• Test operation on a sample: pick a cloud service and pull evidence for each customer responsibility.
• Run an internal tabletop: incident response handoff to provider support, escalation paths, and evidence capture.
• Perform a change-trigger review: confirm how provider changes and internal changes drive matrix updates.
• Prepare an audit packet: matrices, crosswalk, workflow evidence, and exception register export.

Frequently Asked Questions

Do I need a separate shared responsibility matrix for every cloud provider?

You need provider-specific content, but you can start with one template. The key is that responsibilities reflect the actual services you use and assign internal owners per responsibility ¹.

We use mostly PaaS and SaaS. Does shared responsibility still apply?

Yes. The boundary shifts, but it does not disappear. Your matrix should highlight configuration, identity, data handling, and monitoring responsibilities that remain customer-owned even in managed services ¹.

Can I satisfy this requirement by linking to the provider’s shared responsibility webpage?

No for audit purposes. Provider documentation is an input, but you must translate it into your control ownership, procedures, and evidence for your environment ¹.

Who should own the matrix: Security, GRC, or Cloud Platform?

GRC often owns the document control and audit trail, while Cloud Platform and Security Engineering own the technical content. Assign an accountable owner for maintaining the program and accountable owners for each responsibility row.

How do I handle responsibilities that vary by business unit or application team?

Keep the responsibility definition consistent and vary the accountable owner role by environment or application category. Require each app team to attest to ownership during onboarding or architecture review.

What’s the minimum evidence an auditor will accept that it’s “operationalized”?

A current matrix with approvals, a control crosswalk, and workflow artifacts showing it is required for onboarding and updated after material change. Add a sampled evidence pull that demonstrates customer responsibilities are being performed.

Related compliance topics

• 2025 SEC Marketing Rule Examination Focus Areas
• Access and identity controls
• Access Control (AC)
• Access control and identity discipline
• Access control management

Footnotes

1. ISO/IEC 27017 overview