ISO/IEC 27001

⌘K
  1. Home
  2. Docs
  3. ISO/IEC 27001
  4. Other Doc
  5. Cloud Security Risk Assessment

Cloud Security Risk Assessment

1. Purpose

The purpose of the Cloud Security Risk Assessment is to identify, evaluate, and manage information-security risks arising from the use of cloud services.

The assessment provides a structured method for determining:

  • What cloud service is being used
  • What information and systems depend on it
  • Who can access it
  • What threats and vulnerabilities exist
  • What could happen if the cloud service is compromised or unavailable
  • What security controls are already implemented
  • What additional treatment is required
  • What residual risk remains
  • Who approved the resulting risk decision

The assessment should support the organization’s overall information-security risk-management process and Statement of Applicability where applicable.


2. Scope

The assessment may be applied to:

  • IaaS
  • PaaS
  • SaaS
  • Cloud databases
  • Cloud storage
  • Cloud networking
  • Cloud identity services
  • Cloud security platforms
  • Cloud backup services
  • Cloud-hosted applications
  • Containers
  • Serverless services
  • Cloud APIs
  • CI/CD platforms
  • Cloud-based AI/ML services
  • Critical cloud suppliers
  • Cloud services processing customer or personal data

The depth of assessment should be proportionate to the service’s criticality, information handled, access, business dependency, regulatory requirements, and security risk.


3. Core Risk Assessment Principle

The assessment should follow this chain:

Cloud Service → Business Process → Information → Access → Dependency → Threat → Vulnerability → Exposure → Impact → Likelihood → Risk → Controls → Treatment → Residual Risk → Approval → Monitoring

This prevents the assessment from becoming merely a checklist of cloud-provider features.


4. When to Perform the Assessment

A Cloud Security Risk Assessment should be considered:

  • Before introducing a significant new cloud service
  • Before processing sensitive information
  • Before using a cloud service for production
  • When a cloud service becomes business-critical
  • When significant architecture changes occur
  • When new privileged access is introduced
  • When new customer or personal data is processed
  • When data location changes
  • When a new subprocessor is introduced
  • Following a significant security incident
  • Following a major vulnerability
  • During significant supplier changes
  • During periodic ISMS risk reviews
  • When contractual or regulatory requirements change
  • When the organization significantly increases its dependency on a cloud service

Minor or low-risk changes may be handled through the organization’s normal change-management process rather than requiring a full new assessment.


5. Assessment Record

FieldDetails
Assessment IDUnique assessment number
Cloud Service IDReference to Cloud Services Register
Cloud Service NameName of service
ProviderCloud provider
Service TypeIaaS / PaaS / SaaS
Business OwnerResponsible business owner
Technical OwnerTechnical owner
Assessment DateDate performed
Assessment LeadPerson conducting assessment
ReviewersRelevant reviewers
Previous AssessmentReference if applicable
Assessment TriggerNew service / periodic / change / incident etc.
StatusDraft / In Review / Approved / Closed

6. Cloud Service Identification

Document the cloud service being assessed.

Capture:

  • Provider
  • Service name
  • Service type
  • Account/subscription/environment
  • Application supported
  • Business purpose
  • Production/non-production status
  • Service owner
  • Technical owner
  • Supplier ID
  • Criticality

Example:

AWS production environment used to host a customer-facing SaaS application, including application workloads, database, object storage, logging, monitoring, and security services.


7. Business Dependency Assessment

Identify what business activities depend on the cloud service.

Consider:

  • Critical business processes
  • Customer-facing services
  • Revenue-generating activities
  • Internal operations
  • Regulatory processes
  • Security operations
  • Development and deployment
  • Communication
  • Payment processing
  • Customer support

Example

Cloud Service: AWS

Business Dependency: Customer SaaS platform

Impact of prolonged outage: Customers cannot access the application and service delivery is disrupted.


8. Information Assessment

Identify the information processed, stored, or transmitted by the cloud service.

Examples:

  • Customer information
  • Personal data
  • Employee information
  • Application data
  • Source code
  • Financial information
  • Security logs
  • Authentication information
  • Business documents
  • Intellectual property

Record the applicable information classification.

InformationClassificationCloud Service
Customer application dataConfidentialAWS
Security logsInternal/ConfidentialCloud logging platform
Source codeConfidentialGitHub
Employee recordsRestrictedHR SaaS

Classification labels should follow the organization’s approved information-classification scheme.


9. Data Location Assessment

Determine where information may be:

  • Stored
  • Processed
  • Backed up
  • Replicated
  • Transferred

Consider:

  • Primary region
  • Backup region
  • Disaster recovery region
  • Provider processing locations
  • Subprocessor locations
  • International transfers

Example:

Production customer data is hosted in AWS Mumbai, while certain provider support or subprocessors may process limited information in other jurisdictions.

The assessment should consider applicable contractual, privacy, and regulatory requirements.


10. Access Assessment

Identify all significant forms of access.

Consider:

  • Employee access
  • Administrator access
  • Developer access
  • Customer access
  • Supplier access
  • Support access
  • API access
  • Service accounts
  • Machine identities
  • Privileged access
  • Production access

Record whether access is:

  • Individual
  • Shared
  • Role-based
  • Temporary
  • Persistent
  • Privileged

11. Authentication Assessment

Evaluate whether appropriate authentication mechanisms are implemented.

Consider:

  • MFA
  • SSO
  • Federated identity
  • Strong passwords
  • Service accounts
  • API authentication
  • Certificate authentication
  • Privileged authentication
  • Break-glass accounts

Example Finding

Two cloud administrator accounts are not protected by MFA.

Risk: Unauthorized privileged access.

Treatment: Enforce MFA and verify implementation.


12. Privileged Access Assessment

Determine:

  • Who has administrative privileges?
  • Why are privileges required?
  • Is least privilege implemented?
  • Are production permissions restricted?
  • Are privileged activities logged?
  • Are privileged accounts periodically reviewed?
  • Are temporary privileges removed after use?
  • Are emergency accounts controlled?

Privileged cloud access should generally receive enhanced protection because compromise could affect multiple systems and information assets.


13. Cloud Architecture Assessment

Review the relevant architecture.

Consider:

  • Network segmentation
  • Public exposure
  • Private resources
  • Internet-facing services
  • Security groups/firewalls
  • Load balancers
  • Databases
  • Storage
  • APIs
  • Containers
  • Serverless functions
  • Identity services
  • Logging
  • Monitoring
  • Backup
  • Disaster recovery

The assessment should identify architecture-related threats and weaknesses rather than simply recording whether an architecture diagram exists.


14. Configuration Security Assessment

Evaluate whether cloud resources are securely configured.

Examples:

  • Storage not publicly accessible
  • Security groups appropriately restricted
  • Unnecessary ports disabled
  • Administrative interfaces restricted
  • Encryption enabled
  • Logging enabled
  • Secure network configuration
  • Database access restricted
  • Default credentials removed
  • Unused services disabled
  • Security controls consistently configured

Configuration baselines should be aligned with organizational requirements and risk.


15. Encryption Assessment

Evaluate encryption requirements for:

Data at Rest

Examples:

  • Databases
  • Object storage
  • Backups
  • Snapshots
  • Logs

Data in Transit

Examples:

  • Application traffic
  • APIs
  • Administrative connections
  • Service-to-service communication

Also consider:

  • Key management
  • Key access
  • Key rotation
  • Separation of duties
  • Key recovery
  • Compromise response

16. Secrets and Credential Assessment

Identify how the cloud environment manages:

  • Passwords
  • API keys
  • Tokens
  • Access keys
  • Private keys
  • Database credentials
  • Application secrets
  • Certificates

Check whether secrets are stored in approved mechanisms rather than:

  • Source code
  • Git repositories
  • Public storage
  • Unprotected spreadsheets
  • Container images
  • Chat messages

17. Logging and Monitoring Assessment

Evaluate whether security-relevant cloud activities are logged and monitored.

Consider:

  • Authentication
  • Privileged actions
  • API activity
  • Configuration changes
  • Network activity
  • Security alerts
  • Data access
  • Application events
  • Failed login attempts
  • Resource changes

Also assess:

  • Log retention
  • Log protection
  • Alerting
  • Monitoring ownership
  • Investigation process

18. Vulnerability Assessment

Identify vulnerabilities affecting:

  • Operating systems
  • Applications
  • Containers
  • Dependencies
  • Cloud configurations
  • APIs
  • Network services
  • Databases
  • Serverless workloads
  • Infrastructure-as-Code

For each significant finding, consider:

  • Severity
  • Exposure
  • Exploitability
  • Business impact
  • Existing controls
  • Remediation status

A scanner severity should not automatically determine the organization’s final risk rating.


19. Application Security Assessment

For cloud-hosted applications, evaluate:

  • Authentication
  • Authorization
  • Input validation
  • API security
  • Secure coding
  • Dependency management
  • Secrets management
  • Security testing
  • Code review
  • CI/CD security
  • Container security
  • Security monitoring

Where applicable, connect the assessment to the organization’s secure-development process.


20. Network Security Assessment

Consider:

  • Network segmentation
  • Firewall rules
  • Security groups
  • Network ACLs
  • Private endpoints
  • VPN
  • Internet exposure
  • Administrative access
  • Egress controls
  • WAF
  • DDoS protection

Example:

A production database is directly accessible from the internet.

Potential risk: Unauthorized access or exploitation.

Treatment: Remove public exposure and permit access only from authorized application components.


21. Backup and Recovery Assessment

Evaluate:

  • What information is backed up?
  • Backup frequency
  • Backup retention
  • Backup encryption
  • Backup access
  • Backup isolation
  • Recovery process
  • Recovery testing
  • RTO
  • RPO

The assessment should determine whether the backup arrangement is sufficient for the business impact of cloud-service failure.


22. Availability and Resilience Assessment

Consider potential failures involving:

  • Cloud provider outage
  • Availability-zone failure
  • Region failure
  • Database failure
  • Network failure
  • Storage failure
  • Identity-provider failure
  • Key-management failure
  • Third-party dependency
  • Supplier service termination

Evaluate:

  • Redundancy
  • Failover
  • Recovery procedures
  • Alternative arrangements
  • Dependency concentration
  • Recovery testing

23. Supplier and Provider Risk

Assess the cloud provider itself.

Consider:

  • Security assurance
  • Contract
  • SLA
  • Security obligations
  • Incident notification
  • Data protection
  • Subprocessors
  • Data locations
  • Provider dependency
  • Financial/operational stability where relevant
  • Exit capability
  • Provider concentration

The provider’s security certification may be useful evidence, but it does not replace assessment of how the organization uses and configures the service.


24. Shared Responsibility Assessment

Document which controls are the responsibility of:

Cloud Provider

Examples:

  • Physical data center
  • Underlying hardware
  • Certain infrastructure controls

Organization

Examples:

  • IAM
  • User accounts
  • Application security
  • Data classification
  • Configuration
  • Encryption configuration
  • Logging
  • Vulnerability management
  • Backup configuration

Shared

Examples:

  • Security monitoring
  • Incident response
  • Availability
  • Vulnerability management
  • Compliance

The exact responsibility model depends on the cloud service.


25. Subprocessor Assessment

Where applicable, evaluate:

  • Subprocessor identity
  • Service provided
  • Information processed
  • Data location
  • Access
  • Security assurance
  • Contractual controls
  • Incident notification
  • Change notification

Particular attention should be given to subprocessors handling customer or personal data.


26. Cloud Dependency and Concentration Risk

Assess whether the organization is overly dependent on a single cloud provider or technology.

Consider:

  • Single cloud provider
  • Single region
  • Single identity provider
  • Single database technology
  • Single security provider
  • Single backup provider
  • Proprietary cloud services
  • Data portability
  • Migration complexity

A concentration risk does not necessarily mean that multiple providers must be used. The organization should determine whether the dependency is acceptable and what compensating resilience measures are appropriate.


27. Threat Assessment

Identify realistic threats.

Examples:

ThreatExample
Credential compromiseAdministrator credentials stolen
MisconfigurationStorage accidentally made public
Insider misusePrivileged user abuses access
Vulnerability exploitationInternet-facing workload exploited
MalwareMalicious code deployed
Data leakageSensitive data exposed
Cloud outageProvider service unavailable
Supply-chain compromiseThird-party dependency compromised
DDoSApplication becomes unavailable
Unauthorized API accessAPI credentials compromised

Threats should be based on the actual cloud environment rather than a generic threat list.


28. Vulnerability and Exposure Assessment

For each threat, identify relevant vulnerabilities or weaknesses.

Example:

Threat: Unauthorized cloud administration

Vulnerability: Excessive IAM privileges

Exposure: Administrator account can modify production resources

Existing Control: MFA

Additional Control: Least-privilege role redesign and quarterly privileged-access review


29. Risk Assessment

Each identified risk should be assessed using the organization’s approved risk methodology.

A basic structure is:

Risk = Likelihood × Impact

However, the organization’s established methodology should define the actual scoring model.

Example

Risk ElementExample
AssetAWS Production Environment
ThreatCredential compromise
VulnerabilityExcessive privileged access
ExposureProduction administrator role
ImpactHigh
LikelihoodMedium
Inherent RiskHigh
Existing ControlsMFA, logging
TreatmentLeast privilege + access review
Residual RiskMedium

The example is illustrative only.


30. Cloud Risk Register

Significant risks should be recorded in the organization’s risk register or an approved linked risk record.

Recommended fields:

FieldDescription
Risk IDUnique identifier
Cloud Service IDRelated cloud service
Risk DescriptionClear statement of risk
AssetAffected asset
ThreatThreat scenario
VulnerabilityWeakness
ExposureHow threat can act
ImpactBusiness/security impact
LikelihoodLikelihood
Inherent RiskRisk before treatment
Existing ControlsCurrent controls
TreatmentRequired action
OwnerRisk/action owner
Due DateTarget date
Residual RiskRisk after treatment
AcceptanceAcceptance decision
ApprovalAuthorized approver
Review DateNext review
StatusOpen/Closed/etc.

31. Risk Treatment

Treatment should be based on the organization’s approved risk-treatment approach.

Possible approaches include:

Reduce

Implement additional controls.

Example:

Implement MFA and least privilege.

Avoid

Stop using the cloud service where the risk cannot be appropriately managed.

Transfer/Share

Use contractual, insurance, or other arrangements where appropriate.

Accept

Accept the remaining risk through an authorized risk-acceptance process.

Risk acceptance should be formally authorized and should not simply be used to avoid remediation.


32. Cloud Security Treatment Plan

For each significant risk, document:

  • Required control
  • Action
  • Responsible owner
  • Target date
  • Priority
  • Dependencies
  • Required evidence
  • Validation method
  • Residual-risk expectation

Example:

FindingTreatmentOwnerEvidence
Public S3 bucketRestrict public accessCloud EngineerConfiguration evidence
Excessive IAM privilegesRedesign rolesSecurity/CloudIAM review
No recovery testPerform restore testITRecovery test record

33. Residual Risk Assessment

After treatment, reassess the risk.

The assessment should determine:

  • Were controls implemented?
  • Are they operating?
  • Has exposure decreased?
  • Has likelihood changed?
  • Has impact changed?
  • Is additional treatment required?
  • Is remaining risk acceptable?

Example:

Inherent Risk: High

↓ MFA + least privilege + monitoring

Residual Risk: Medium

The residual-risk decision should follow the organization’s approved risk methodology and acceptance authority.


34. AWS SaaS Example

A SaaS startup hosts its production platform on AWS.

Architecture includes:

  • ECS/EC2
  • RDS
  • S3
  • IAM
  • KMS
  • CloudTrail
  • CloudWatch
  • WAF

Scenario

A review identifies that several developers have broad production IAM permissions.

Threat: Compromised developer account.

Vulnerability: Excessive IAM permissions.

Exposure: Developer account can modify production infrastructure and access sensitive resources.

Potential Impact:

  • Customer data exposure
  • Application disruption
  • Unauthorized configuration changes
  • Security incident
  • Customer trust impact

Existing Controls:

  • MFA
  • CloudTrail
  • Security monitoring

Treatment:

  • Implement role-based least privilege
  • Separate development and production permissions
  • Restrict privileged production access
  • Perform periodic access reviews
  • Monitor privileged actions

Verification Evidence:

  • IAM role configuration
  • Access review
  • CloudTrail evidence
  • Security monitoring configuration
  • Approved risk treatment record

Residual Risk: Reassess after implementation.


35. Cloud Risk Assessment Summary

At the end of the assessment, summarize:

Key Risks

List significant identified risks.

Key Controls

List important existing controls.

Security Gaps

Identify unresolved weaknesses.

Required Actions

Identify corrective/treatment actions.

Residual Risk

Document remaining risk.

Decision

Possible organizational decisions include:

  • Approved
  • Approved with Conditions
  • Further Assessment Required
  • Treatment Required
  • Risk Accepted
  • Service Not Approved

These are organizational decision options, not ISO-prescribed outcomes.


36. Approval

The assessment should be reviewed and approved by appropriate stakeholders based on risk.

Depending on the organization, this may include:

  • Business Owner
  • Technical Owner
  • Information Security
  • Privacy
  • IT/Cloud Team
  • Risk Owner
  • Senior Management

Higher-risk cloud services should receive appropriate management oversight.


37. Monitoring and Reassessment

Cloud risk should not be treated as a one-time assessment.

Reassessment should occur when there is:

  • Major cloud architecture change
  • Security incident
  • Significant vulnerability
  • New data processing
  • New privileged access
  • New subprocessor
  • Data-location change
  • Significant provider change
  • Major outage
  • Increased business dependency
  • Material contractual change
  • Regulatory change
  • Significant change in threat environment

Periodic reassessment should also be performed according to the organization’s risk-management requirements.


38. Evidence Register

Maintain references to evidence supporting the assessment.

EvidenceExample
Cloud architectureArchitecture diagram
IAMAccess review
MFAIdentity configuration
ConfigurationCloud security assessment
EncryptionKMS/configuration evidence
LoggingCloudTrail configuration
MonitoringCloudWatch/security monitoring
VulnerabilityVulnerability report
BackupBackup configuration
RecoveryRecovery test
SupplierISO/SOC evidence
ContractCloud agreement
DPAData Processing Agreement
RiskApproved risk assessment
TreatmentCorrective action evidence

Evidence should be stored in the organization’s approved repository.

Secrets and credentials must never be stored as assessment evidence.


39. Relationship With Other ISMS Documents

DocumentRelationship
Cloud Security PolicyDefines cloud-security requirements
Cloud Services RegisterIdentifies the cloud service being assessed
Asset RegisterIdentifies affected information assets
Risk RegisterRecords significant cloud risks
Risk Treatment PlanTracks treatment actions
Statement of ApplicabilityRecords applicable ISO controls
Supplier Risk AssessmentAssesses provider-related risk
Critical Supplier RegisterIdentifies critical providers
ICT Dependency RegisterRecords cloud dependencies
Access ReviewValidates cloud access
Vulnerability RegisterTracks vulnerabilities
Incident RegisterRecords cloud incidents
Business Continuity PlanAddresses cloud disruption
Backup PolicyDefines backup requirements
Change ManagementControls significant cloud changes

40. Common Mistakes

1. Treating the provider as the entire risk

“AWS is ISO certified, therefore our cloud is secure.”

Provider assurance does not establish that the organization’s IAM, configuration, applications, data, or operational processes are secure.

2. Only checking technical controls

Business dependency, customer impact, privacy, availability, concentration, and exit risks should also be considered.

3. No data-flow assessment

The assessment should identify where information is stored, processed, replicated, and transferred where relevant.

4. Ignoring privileged access

Cloud administrator access can create significant exposure.

5. No residual-risk decision

Closing findings without reassessing the remaining risk weakens the risk-management trail.

6. Treating vulnerability severity as the entire risk

A vulnerability should be evaluated in context of exposure, exploitability, existing controls, and business impact.

7. Assessment never updated

Cloud architecture and risks change continuously.


41. Internal Audit Checklist

An auditor may verify:

  • Is the cloud service identified?
  • Is it recorded in the Cloud Services Register?
  • Is the business purpose documented?
  • Are business dependencies identified?
  • Is information processed identified?
  • Is information classification defined?
  • Is customer/personal data identified?
  • Is data location understood?
  • Are users and privileged users identified?
  • Is MFA implemented where required?
  • Is least privilege assessed?
  • Is cloud architecture reviewed?
  • Are configuration risks assessed?
  • Is encryption assessed?
  • Are secrets protected?
  • Are logging and monitoring assessed?
  • Are vulnerabilities considered?
  • Are backup and recovery assessed?
  • Is availability considered?
  • Is supplier risk assessed?
  • Are subprocessors considered?
  • Is concentration/dependency risk considered?
  • Are significant risks recorded?
  • Are treatment actions assigned?
  • Is residual risk assessed?
  • Is risk acceptance formally approved where applicable?
  • Is evidence available?
  • Is the assessment periodically reviewed?
  • Are material changes triggering reassessment?

42. ISO 27001 Connection

The Cloud Security Risk Assessment supports the organization’s risk-based ISMS by connecting cloud usage with information-security risks and controls.

It can provide evidence supporting areas such as:

  • Cloud service security
  • Information classification
  • Access control
  • Identity management
  • Privileged access
  • Supplier management
  • ICT supply-chain security
  • Configuration management
  • Logging and monitoring
  • Vulnerability management
  • Backup
  • Network security
  • Secure development
  • Incident management
  • Business continuity

The assessment itself is an organizational risk-management tool. ISO 27001 does not require every organization to use this exact template.

The organization should determine the required assessment depth based on its ISMS scope, risk methodology, cloud usage, applicable controls, legal/regulatory obligations, contractual requirements, and business context.


43. Final Cloud Security Risk Audit Trail

A complete assessment should demonstrate:

Cloud Service Identified

↓
Business Dependency

↓
Information Identified

↓
Data Location

↓
Access & Privileged Access

↓
Architecture & Configuration

↓
Threat Identification

↓
Vulnerability / Exposure

↓
Business Impact

↓
Likelihood

↓
Inherent Risk

↓
Existing Controls

↓
Risk Treatment

↓
Control Implementation

↓
Verification

↓
Residual Risk

↓
Risk Acceptance / Further Treatment

↓
Approval

↓
Monitoring

↓
Periodic Reassessment


44. Final Principle

A useful Cloud Security Risk Assessment should answer seven questions:

What cloud service are we using?

What business and information depend on it?

Who can access it?

What could go wrong?

What controls protect it?

What risk remains after those controls?

Who accepted or treated that remaining risk, and how do we know the controls continue to work?

The objective is not to prove that the cloud provider is secure. The objective is to demonstrate that the organization understands and manages the security risks created by its own use of cloud services.

How can we help?

Leave a Reply

Your email address will not be published. Required fields are marked *