Shared Responsibility Model Misconceptions: Real Cloud Risk Scenarios
The Shared Responsibility Model (SRM) is a cornerstone of cloud security, yet it remains widely misunderstood. Many organizations assume that by moving to the cloud, they have transferred most or all of their security responsibilities to the provider. This misconception has led to countless misconfigurations, data exposures, and compliance failures.
In this article, we explore how the Shared Responsibility Model really works, break down common misunderstandings, and highlight real-world cloud security risks resulting from these gaps.
Understanding the Shared Responsibility Model
The Shared Responsibility Model defines which security responsibilities are handled by the cloud provider and which remain with the customer. Cloud providers such as AWS, Microsoft Azure, and Google Cloud maintain and secure the infrastructure that supports cloud services. However, customers are still responsible for securing what they deploy and configure on those services.
Core Responsibilities
| Cloud Provider Responsibility | Customer Responsibility |
|---|---|
| Physical security of data centers | Configuration of cloud services (e.g., access controls, storage permissions) |
| Network infrastructure and platform software | Application-level security and vulnerability management |
| Managed service availability | Identity and access management (IAM), secrets, and key management |
| Hypervisor and managed OS patching | Operating system patching (in IaaS), middleware and runtime configurations |
| Global infrastructure redundancy | Data encryption, classification, backups, and monitoring |
The distribution of responsibility also varies based on the service model being used—Infrastructure as a Service (IaaS), Platform as a Service (PaaS), Software as a Service (SaaS), or serverless computing.
Service Model Variations
| Service Model | Cloud Provider Covers | Customer Covers |
|---|---|---|
| IaaS | Virtualization, storage, networking | OS, applications, IAM, data, configurations |
| PaaS | Runtime, middleware, managed OS | Application code, data handling, user access, policy enforcement |
| SaaS | Application, platform, infrastructure | Access management, user activity monitoring, data security and compliance |
| Serverless | Execution platform and auto-scaling | Code security, IAM policies, API exposure, event input validation |
Common Misconceptions
Misconception 1: “The provider handles everything.”
This is the most common error. While providers manage the infrastructure, customers are responsible for securing their workloads, configurations, user access, and data.
Misconception 2: “SaaS means zero responsibility.”
Even with SaaS offerings like Microsoft 365 or Salesforce, customers must implement access controls, enforce security policies, and meet regulatory compliance obligations. Many breaches occur due to misconfigured SaaS policies or inactive account misuse.
Misconception 3: “Default configurations are secure.”
Cloud environments prioritize flexibility. Defaults are not always secure. For instance, object storage buckets may be public unless explicitly restricted. Overly permissive IAM roles, unused access keys, and open ports are frequent sources of exposure.
Misconception 4: “Patching is the provider’s job.”
This only applies to fully managed services. In IaaS environments, customers are responsible for patching the operating system and all software they install.
Misconception 5: “Cloud compliance is inherited.”
Cloud providers offer compliance for their infrastructure, not for the customer’s implementation. If you store unencrypted PII in an S3 bucket or fail to log access to sensitive systems, you are not compliant—regardless of the provider’s certifications.
Bonus: Serverless Is Not Security-Free
Serverless computing simplifies infrastructure management but still requires customers to secure code, manage IAM permissions, and validate event inputs. Function-level access should be strictly limited, and secrets should never be hardcoded into functions.
Real-World Scenario: Misconfig + Misunderstanding
A healthcare SaaS platform deployed on AWS used S3 for storing sensitive client data. Developers believed encryption and access controls were handled by default. However, the S3 bucket was publicly accessible and lacked server-side encryption. The exposure went unnoticed for several weeks, potentially violating HIPAA requirements.
Upon discovery, the company:
- Enabled encryption-at-rest with customer-managed keys
- Revised IAM roles and access logs
- Implemented monitoring through AWS Config and GuardDuty
- Delivered cloud security training to engineering teams
Actionable Guidance
Organizations can reduce cloud risks by taking ownership of their responsibilities under the Shared Responsibility Model. Recommendations include:
- Map your architecture to service models (IaaS, PaaS, SaaS, Serverless) and define ownership across teams.
- Use cloud security posture management (CSPM) tools to detect misconfigurations and drift.
- Implement least privilege access and enforce regular key and permission reviews.
- Encrypt data in transit and at rest and use tagging for classification and control.
- Train engineers and DevOps staff on security best practices and SRM specifics.
- Establish a cloud governance model that integrates with your broader GRC program.
- Continuously monitor configurations and logs using native or third-party tools.
Final Thoughts
The Shared Responsibility Model is not simply a conceptual framework—it defines the line between proactive security and preventable failure. As organizations increasingly rely on cloud infrastructure, understanding and acting on your responsibilities within this model is essential.
Failure to internalize SRM leads to misconfigurations, overlooked compliance obligations, and cloud-native risks. Clarity in roles, ownership, and accountability must be foundational to every cloud initiative.
Ready to Strengthen Your Cloud Security?
Anchor Cyber Security helps organizations:
- Conduct cloud security posture reviews
- Map cloud responsibilities to compliance frameworks
- Build defensible cloud governance strategies
To schedule a Shared Responsibility Model workshop or speak with a cloud advisor, contact us today!