Framework - ISO 27001 (Cyber)

Cloud adoption has fundamentally redefined how organizations manage technology, risk, and trust. Controls A.5.23 and A.5.24 were written for this new landscape, where business speed often outpaces traditional governance and where shared responsibility replaces total ownership. The intent of A.5.23 is to ensure that the use of cloud services—whether infrastructure, platform, or software—is deliberate, risk-informed, and verifiably controlled. This means every migration, integration, or new workload must have a security justification and an evidence trail linking decisions to defined policies. Shared-responsibility boundaries must be mapped before deployment so both the organization and the provider understand who manages each safeguard. A.5.24 builds on that foundation by ensuring incident management readiness is adapted to this cloud-first reality. Together, these controls create a security posture that balances agility with accountability: the cloud becomes not a blind trust model, but a managed extension of the organization’s governance framework.

The scope of A.5.23 reaches across all forms of cloud consumption—Infrastructure as a Service, Platform as a Service, Software as a Service, and even the growing realm of serverless and container-based services. It applies to every environment that touches organizational data, from production workloads to development and testing environments. It also explicitly addresses “shadow IT,” where teams may adopt cloud solutions outside formal procurement. Hybrid and multi-cloud strategies bring additional complexity, requiring policies that ensure consistent protection as data moves between providers and regions. Security controls must align with the organization’s data classification system and residency requirements so that sensitive information is stored and processed only in compliant jurisdictions. This comprehensive scope transforms cloud from a patchwork of convenience into an orchestrated environment governed by clear, measurable security expectations.

Selecting a cloud service provider becomes an exercise in risk-based due diligence rather than a procurement shortcut. Each provider’s capabilities must map directly to the organization’s control framework, covering access control, encryption, monitoring, and compliance support. Certifications such as ISO/IEC 27001, SOC 2 Type II, and FedRAMP provide a baseline for assurance but must be validated through supporting evidence and current attestations. Data residency options and region-level compliance offerings help meet privacy and regulatory requirements. Evaluating the tenant isolation model ensures workloads remain segregated from other customers, while identity federation and single sign-on capabilities confirm that authentication integrates seamlessly into enterprise directories. Logging, export, and retention capabilities should be reviewed for investigatory sufficiency—without the ability to retrieve forensic logs, even the best security policies become unenforceable. Through this vetting process, organizations ensure that cloud providers become allies in assurance rather than sources of uncertainty.

Once a provider is selected, onboarding controls establish a secure foundation for every new cloud account, project, or tenant. A well-defined “account factory” or landing zone enforces baseline configurations from day one. Network segmentation policies, private endpoints, and virtual private clouds restrict exposure by default. Key management ownership must remain with the organization wherever feasible, ideally using customer-controlled encryption keys or hardware security modules. Service control policies enforce least-privilege defaults, preventing users or automated tools from enabling high-risk services without approval. Change management frameworks integrate with provider APIs to capture configuration events automatically, maintaining a live record of what has been altered. These onboarding guardrails transform the early cloud setup process into a security control checkpoint, ensuring consistency across teams and reducing the likelihood of risky improvisation later.

Operational assurance and observability turn visibility into the backbone of cloud governance. Centralized logging aggregates telemetry from multiple providers into a unified system, feeding security information and event management platforms. Immutable storage, such as write-once-read-many (WORM) repositories, protects logs from alteration. Cloud-native threat detection tools integrate with third-party intelligence feeds, correlating activity across services and tenants to detect subtle signs of compromise. Configuration drift detection identifies when security settings deviate from baselines, allowing remediation before exposure grows. Backup and restore capabilities must be tested routinely—automation can ensure these tests occur across different regions and scenarios to simulate real-world failures. Observability converts operational noise into measurable assurance, giving leaders confidence that risks are being monitored continuously, not episodically.

Supplier management and exit strategy readiness complete the lifecycle perspective of A.5.23. Cloud providers must be treated like any critical supplier—evaluated, monitored, and governed by enforceable contracts. Portability must be designed into every architecture, ensuring that the organization can retrieve data or move workloads without disruption or lock-in. Data egress mechanisms and verified deletion processes guarantee that information does not linger after a service is terminated. Outage contingencies—whether for region-level incidents, geopolitical instability, or provider insolvency—must include tested fallback environments and business continuity procedures. Contractual clauses should establish joint incident cooperation requirements, defining how evidence will be shared and who retains investigative authority. These measures ensure that cloud reliance never becomes cloud dependence; control and accountability remain with the customer, even in shared environments.

A.5.23 therefore represents a comprehensive evolution in risk management—one where technology enablement and security governance coexist. It formalizes what leading organizations already understand intuitively: that the cloud can deliver scale and innovation only when built upon deliberate structure and visible accountability. From selecting providers and hardening environments to managing identity, data, and continuity, every step of cloud adoption under this control produces tangible evidence of due diligence. This evidence becomes the foundation for A.5.24, which turns preparation into readiness—ensuring that when incidents occur, the organization’s people, tools, and processes can respond with speed, accuracy, and confidence.

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Incident management planning and preparation, captured in control A.5.24, is the organization’s insurance policy against chaos. No system, cloud or otherwise, is immune to disruption, and no prevention measure is perfect. This control ensures that when something goes wrong, responses are structured, pre-authorized, and measurable. A.5.24 requires that the organization maintain a formal, organization-wide incident management framework defining roles, authority lines, and decision criteria. These structures must include both on-premises and cloud service contexts so that responses remain coherent across hybrid environments. Cloud-specific runbooks need to be integrated within the broader incident playbook library, outlining how containment, evidence gathering, and communication occur in each major service model. The ultimate goal is readiness—not just to detect incidents but to respond effectively, preserving evidence and ensuring that business continuity is restored with minimum disruption.

The scope of incident planning under A.5.24 extends far beyond technical forensics. It encompasses governance, communication, coordination, and recovery. Every organization must maintain an incident playbook architecture that covers the full spectrum of likely events—credential theft, data leaks, ransomware outbreaks, insider abuse, and cloud service outages. These playbooks should include decision trees with clear go/no-go criteria for escalation, isolation, and external reporting. Each scenario also requires pre-approved communication templates for internal briefings, customer notifications, and regulatory disclosures. Legal and compliance triggers must be embedded into these workflows, ensuring that notification deadlines and jurisdictional requirements are met without confusion. By designing this architecture in advance, organizations transform reactive panic into disciplined execution when real crises occur.

Preparedness ultimately depends on people and practice. Maintaining an up-to-date on-call roster ensures that the right expertise is available around the clock, while clearly defined escalation ladders remove guesswork during high-pressure events. Regular tabletop exercises test strategic decision-making, while red-team and blue-team drills simulate realistic attack and defense conditions. Cross-team rehearsals that include cloud service providers or critical vendors confirm that external partners can collaborate smoothly during real incidents. Each exercise should conclude with an after-action review (AAR) documenting what worked, what failed, and how processes or playbooks must be updated. These rehearsals build muscle memory, allowing staff to move instinctively under pressure rather than hesitating amid uncertainty. Preparedness, like security itself, is sustained through repetition, not documentation alone.

Effective incident response relies on coordination among suppliers, authorities, and customers. Joint investigation protocols with cloud providers or third-party partners define who leads, who supports, and how information is exchanged. Notification pathways must be time-bound—some regulations require disclosure within 24 or 72 hours, depending on the nature of the incident. Secure artifact-exchange channels, such as encrypted repositories or portals, prevent further leakage during collaboration. Coordination must also align with prior contractual terms defined in A.5.5 and A.5.20, ensuring obligations like breach notification, data handling, and liability are already established. By pre-negotiating these roles and processes, organizations prevent confusion at the worst possible time—when every minute counts, and credibility is at stake.

Resilience and continuity planning ensure that incident management connects seamlessly with recovery objectives. Each playbook should identify priority restoration sequences based on critical business functions and service dependencies. For example, restoring customer-facing portals may take precedence over internal analytics systems. Fallback environments—such as secondary cloud regions, backup tenants, or on-premises contingencies—must be tested routinely, not only for technical viability but for performance under pressure. Data seeding ensures that restored environments have current and usable information, minimizing downtime. Dependency maps should be reviewed after every major event, updating interconnections that influence recovery paths. This continuous linkage between incident response and business continuity ensures that resilience is not an abstract principle but a measurable, actionable discipline.

Metrics are the lens through which readiness is assessed. Common indicators include mean time to detect, contain, eradicate, and recover from incidents (MTTD, MTTC, MTTE, and MTTR). Exercise completion rates and the percentage of identified gaps remediated provide insight into maturity. The success or defect rate of evidence collection shows whether forensic readiness is more than theoretical. Compliance with regulatory or contractual notification timelines demonstrates operational discipline. Collectively, these metrics turn incident response from anecdote to analytics, giving leadership visibility into real-world performance and enabling continuous improvement cycles grounded in measurable outcomes rather than assumptions.

Yet even with clear frameworks, organizations still encounter pitfalls. One of the most common is unclear boundaries within the shared-responsibility model—assuming the cloud provider will handle incident response for layers the customer still owns. Another is insufficient logging or export rights embedded in contracts, leaving customers blind when issues occur. Ad-hoc responder access, often granted under duress, can lead to uncontrolled actions that compromise evidence. Many teams fail to update playbooks after significant changes in their cloud architectures, leaving them mismatched to reality. Each of these pitfalls underscores the same lesson: incident readiness must evolve as the environment evolves. Stagnant plans invite chaos when disruption strikes.

Mature organizations adopt scalable good practices that turn these controls into living systems. Cloud landing zones enforce policy-as-code, ensuring consistent baseline configurations and enabling automatic rollback of unauthorized changes. Continuous control monitoring tools verify compliance in real time, alerting teams when settings drift or new services appear unexpectedly. Quarterly joint exercises with major cloud providers or key vendors reinforce coordination and trust while refining communication channels. Most importantly, lessons learned from every incident or exercise feed directly into change management, risk assessment, and updates to the Statement of Applicability. In this way, the cycle of readiness becomes self-improving, constantly strengthening the organization’s defensive reflexes.

Together, A.5.23 and A.5.24 ensure that the cloud is not a source of uncertainty but a well-governed extension of enterprise infrastructure. A.5.23 governs how cloud services are chosen, configured, and monitored, ensuring control and observability. A.5.24 ensures the people and processes supporting those services can respond to disruption with precision, speed, and confidence. Clear responsibility boundaries, rehearsed playbooks, and measurable readiness indicators sustain assurance across this entire digital ecosystem. These controls represent the culmination of preventive and preparatory governance—laying the groundwork for what follows in A.5.25 and A.5.26, where the focus shifts from readiness to real-time execution and evidence handling during active incidents.