OCI Shared Security Model

Introduction

The Primary Goal of the Oracle Cloud Infrastructure Shared Security Model is to clearly define the security responsibilities between Oracle and customers using Oracle Cloud Infrastructure (OCI). In modern cloud environments, security is not handled entirely by the cloud provider or entirely by the customer. Instead, both parties share responsibility for protecting infrastructure, applications, workloads, and data.

In Oracle Cloud Infrastructure, Oracle secures the underlying cloud platform, while customers are responsible for securing their own configurations, identities, applications, operating systems, and business data. Understanding this shared responsibility model is extremely important for OCI administrators, architects, security consultants, and implementation teams working on enterprise cloud projects.

Organizations migrating workloads from on-premises environments to OCI often assume that moving to the cloud automatically transfers all security responsibilities to Oracle. In real-world implementations, this assumption creates major risks such as exposed public buckets, weak IAM policies, improper VCN security rules, and unpatched compute instances.

This article explains the Oracle Cloud Infrastructure Shared Security Model in detail, including architecture concepts, responsibilities, implementation examples, security best practices, and common mistakes seen in real OCI projects.

What is the Oracle Cloud Infrastructure Shared Security Model?

The Oracle Cloud Infrastructure Shared Security Model is a framework that defines:

• What Oracle secures
• What the customer secures
• How both parties collaborate to maintain cloud security

The model ensures that security responsibilities are properly divided between the cloud service provider and the customer organization.

In OCI:

• Oracle is responsible for the security OF the cloud
• Customers are responsible for the security IN the cloud

This distinction is extremely important during OCI implementations.

Why the Shared Security Model is Important in OCI

Cloud environments are fundamentally different from traditional on-premises infrastructure.

In an on-premises data center, the organization manages:

• Physical servers
• Network devices
• Storage hardware
• Virtualization
• Security controls
• Applications
• Database security

In OCI, Oracle manages the foundational infrastructure, reducing operational overhead. However, customers still retain responsibility for their workloads and configurations.

The primary goal of the shared security model is to:

• Reduce security confusion
• Prevent responsibility gaps
• Ensure compliance
• Improve governance
• Protect customer data
• Establish accountability

Without a shared security model, organizations may incorrectly assume Oracle handles all aspects of security, which can lead to major vulnerabilities.

Oracle Responsibility in the Shared Security Model

Oracle secures the underlying cloud infrastructure that runs OCI services.

Oracle Responsibilities Include

Oracle continuously monitors the OCI environment to maintain service availability and infrastructure protection.

Customer Responsibility in the Shared Security Model

Customers are responsible for securing workloads deployed inside OCI.

Customer Responsibilities Include

In real OCI implementations, most security incidents occur because of customer-side misconfigurations rather than Oracle infrastructure vulnerabilities.

Core Principle of the Shared Security Model

The core principle is simple:

Oracle protects the cloud platform.

Customers protect their workloads and data.

This shared approach ensures:

• Better scalability
• Faster cloud adoption
• Reduced infrastructure management
• Improved enterprise security posture

Shared Security Responsibilities by OCI Service Type

Security responsibilities vary slightly depending on the OCI service model.

Infrastructure as a Service (IaaS)

Examples:

• OCI Compute
• OCI Block Volumes
• OCI Networking

Oracle Manages

• Physical infrastructure
• Hypervisor
• Cloud hardware

Customer Manages

• Guest OS
• Applications
• Firewalls
• Middleware
• Data security

Platform as a Service (PaaS)

Examples:

• Autonomous Database
• Oracle Integration Cloud
• Oracle Analytics Cloud

Oracle Manages

• Infrastructure
• Runtime platform
• Platform patching

Customer Manages

• User access
• Data
• Business configurations
• Integrations

Software as a Service (SaaS)

Examples:

• Oracle Fusion HCM
• Oracle ERP Cloud
• Oracle SCM Cloud

Oracle Manages

• Infrastructure
• Application maintenance
• Platform patching

Customer Manages

• Users
• Roles
• Data access
• Business process controls

Real-World Implementation Scenarios

Scenario 1 – Publicly Exposed Object Storage Bucket

A retail company migrated invoice files to OCI Object Storage.

Problem:

• The storage bucket was accidentally configured as public.

Result:

• Sensitive documents became accessible externally.

Oracle Responsibility:

• Oracle secured the storage infrastructure.

Customer Responsibility:

• Bucket access configuration.

Lesson:
The customer must properly configure OCI IAM and bucket visibility settings.

Scenario 2 – Weak IAM Policies

A financial company granted:

Allow group Developers to manage all-resources in tenancy

This overly permissive policy allowed accidental production changes.

Oracle Responsibility:

• IAM platform security.

Customer Responsibility:

• Policy configuration.

Best Practice:
Use least-privilege access policies.

Scenario 3 – Unpatched Compute Instance

An organization deployed Linux compute instances but never patched the OS.

Result:

• Vulnerability exploitation occurred.

Oracle Responsibility:

• OCI infrastructure security.

Customer Responsibility:

• Guest operating system patching.

Architecture of OCI Shared Security Model

A simplified OCI security architecture includes:

+--------------------------------------------------+
| Customer Applications and Data                   |
+--------------------------------------------------+
| Operating Systems and Middleware                 |
+--------------------------------------------------+
| Virtual Machines / Containers                    |
+--------------------------------------------------+
| OCI Virtualization Layer                         |
+--------------------------------------------------+
| Physical Servers and Networking                  |
+--------------------------------------------------+
| Oracle Data Center Security                      |
+--------------------------------------------------+

Oracle Secures

• Lower infrastructure layers

Customer Secures

• Upper workload layers

Key OCI Security Services Supporting the Shared Security Model

OCI provides several services that help customers fulfill their security responsibilities.

Identity and Access Management (IAM)

OCI IAM controls authentication and authorization.

Common Features

• Users
• Groups
• Policies
• Dynamic groups
• Federation
• MFA

Example IAM Policy

Allow group FinanceAdmins to manage autonomous-database in compartment FINANCE

Virtual Cloud Network (VCN)

Customers secure network communication using:

• Security lists
• Network Security Groups
• Route tables
• Gateways

Example Security Rule

Allow HTTPS traffic:

Ingress TCP Port 443 from 0.0.0.0/0

OCI Vault

OCI Vault helps customers manage:

• Encryption keys
• Secrets
• Certificates

This supports enterprise encryption requirements.

Cloud Guard

OCI Cloud Guard continuously monitors OCI resources for security risks.

Cloud Guard Detects

• Public buckets
• Weak IAM policies
• Unencrypted resources
• Suspicious activity

Security Zones

Security Zones enforce security best practices automatically.

Example restrictions:

• No public IPs
• Mandatory encryption
• Restricted internet access

These controls help prevent accidental misconfigurations.

Logging and Monitoring

Customers should enable:

• Audit logs
• Service logs
• Flow logs
• Monitoring alarms

These services improve visibility and incident response.

Step-by-Step Security Setup in OCI

Step 1 – Create Compartments

Navigation:

OCI Console → Identity & Security → Compartments

Example:

• PROD
• DEV
• TEST

Compartments isolate resources securely.

Step 2 – Configure IAM Policies

Navigation:

Identity & Security → Policies

Example Policy:

Allow group NetworkAdmins to manage virtual-network-family in compartment PROD

Step 3 – Enable MFA

Navigation:

Identity & Security → Users → MFA Settings

Multi-factor authentication improves account protection.

Step 4 – Configure Network Security

Navigation:

Networking → Virtual Cloud Networks

Create:

• Security Lists
• NSGs
• Route Tables

Restrict unnecessary ports.

Step 5 – Enable Cloud Guard

Navigation:

Security → Cloud Guard

Configure:

• Detector recipes
• Responder recipes
• Reporting

Step 6 – Configure Logging

Navigation:

Observability & Management → Logging

Enable:

• Audit logs
• Resource logs

Testing the Security Configuration

After implementing security controls, testing is mandatory.

Example Validation Tests

Common Security Mistakes in OCI Implementations

1. Overly Broad IAM Policies

Problem:

Allow group Admins to manage all-resources in tenancy

Risk:

• Excessive permissions

2. Open Security Rules

Problem:
Allowing SSH from all IP addresses.

Risk:

• Brute force attacks

3. Ignoring Logging

Without logging:

• Incidents become difficult to investigate.

4. Missing Encryption

Sensitive data without encryption increases compliance risks.

5. Lack of Compartment Design

Poor compartment strategy causes governance issues.

Best Practices for OCI Shared Security

Use Least Privilege Access

Grant only required permissions.

Enable Multi-Factor Authentication

Mandatory for administrators.

Use Security Zones

Prevent accidental insecure configurations.

Regularly Patch Compute Instances

OS vulnerabilities remain customer responsibility.

Enable Cloud Guard

Continuously monitor risks.

Separate Environments

Use separate compartments for:

• DEV
• TEST
• PROD

Rotate Secrets Regularly

Use OCI Vault for secure secret management.

Implement Network Segmentation

Use private subnets whenever possible.

Monitor Audit Logs

Review suspicious activities regularly.

Conduct Security Reviews

Periodic assessments improve cloud security posture.

OCI Shared Security Model vs Traditional Data Centers

How the Shared Security Model Supports Compliance

OCI helps organizations comply with:

• GDPR
• HIPAA
• SOC
• ISO 27001
• PCI-DSS

Oracle provides compliant infrastructure, but customers must configure workloads properly to meet regulatory requirements.

Example:
A healthcare organization using OCI must still configure:

• Encryption
• Access restrictions
• Audit logging

Even though Oracle maintains compliant infrastructure.

Frequently Asked Questions (FAQs)

1. What is the main purpose of the OCI Shared Security Model?

The main purpose is to define security responsibilities between Oracle and customers to ensure secure cloud operations.

2. Does Oracle handle operating system patching in OCI Compute?

No. Customers are responsible for patching guest operating systems running on OCI Compute instances.

3. What security services are available in OCI?

OCI provides services such as:

• IAM
• Cloud Guard
• Vault
• Security Zones
• Logging
• Web Application Firewall

Expert Consultant Tips

Design IAM Early

Many OCI projects fail because IAM is designed too late.

Never Use Tenancy-Wide Admin Access for Daily Operations

Use compartment-based administration wherever possible.

Use Infrastructure as Code

Terraform helps standardize secure deployments.

Automate Security Monitoring

Cloud Guard and Logging Analytics reduce manual monitoring effort.

Review Security Policies Quarterly

Security requirements evolve continuously.

Summary

The Primary Goal of the Oracle Cloud Infrastructure Shared Security Model is to establish a clear division of security responsibilities between Oracle and customers. Oracle secures the cloud infrastructure, while customers secure workloads, configurations, applications, and data deployed within OCI.

Understanding this model is essential for designing secure OCI environments, preventing security incidents, meeting compliance requirements, and implementing enterprise-grade cloud governance.

In real-world OCI implementations, most vulnerabilities occur because of customer misconfigurations such as weak IAM policies, open network rules, unpatched compute instances, or publicly exposed storage buckets. Organizations that properly understand and implement the shared security model achieve stronger cloud security, better operational control, and improved compliance readiness.

For additional information, refer to the official Oracle Cloud Infrastructure documentation:

Oracle Cloud Infrastructure Documentation

Also review Oracle’s official security documentation:

OCI Security Documentation