Shared Responsibility in the Cloud: Why It’s Still Misunderstood

Let’s play a quick game.

Who’s responsible for securing your cloud resources?

A) You
B) Your cloud provider
C) “Uh… both?”

If you picked C, congratulations — you’re technically right. But here’s the problem: most teams stop there. They’ve heard about the “Shared Responsibility Model,” nodded politely during onboarding, and went back to assuming that Azure, AWS, or Google Cloud has everything covered.

Spoiler: they don’t.

In fact, shared responsibility is probably the most misunderstood concept in cloud security today.

The Myth of the Magic Cloud

The biggest misconception I still hear is that moving to the cloud somehow means “security handled.”

“Oh, we’re in Azure now - Microsoft handles that.”
Or, “We use AWS - they’re secure by default.”

Right. And by that logic, buying a house means the insurance company locks your doors for you.

Cloud providers secure the cloud, not your stuff in it. They handle the physical data centers, the hardware, the network backbone, and some platform services. But you handle everything you deploy on top; your configurations, your code, your data, and your access controls.

It’s not glamorous, but it’s the truth.

So What Is the Shared Responsibility Model?

At its core, the model divides security tasks between the provider and the customer.

• Infrastructure as a Service (IaaS): You handle most of the stack — OS hardening, network configuration, access management — while your provider keeps the servers and physical security locked down.

• Platform as a Service (PaaS): You lose some control (and responsibility) as the provider manages more of the platform — but you’re still in charge of identity, code, and data.

• Software as a Service (SaaS): The provider does almost everything, yet you’re still responsible for things like data governance, user access, and compliance.

It’s simple enough in a slide deck. But in the real world? It gets messy… fast.

Why It’s Still So Misunderstood

1. Managed services blur the lines.
Take Azure Kubernetes Service (AKS). The control plane is managed by Microsoft, but your cluster configurations, RBAC, secrets, and network policies are all on you. People often think “managed” means “secured,” but that’s like assuming your landlord also does your laundry.

2. Assumed coverage is dangerous.
Many teams assume the provider handles backups, patching, or encryption automatically. (They might or they might not. Spoiler: you should check.)

3. Cloud docs tell you what they do not what they don’t.
AWS, Azure, and Google Cloud all describe their shared responsibility models, but rarely do they point out the things they explicitly don’t do. The devil lives in the footnotes.

4. Siloed teams = shared chaos.
DevOps thinks the security team has it covered. Security assumes DevOps does. Meanwhile, an S3 bucket goes public. No one meant for it to happen but no one knew they were responsible either.

A Real Example: Securing Azure Kubernetes Service (AKS)

Let’s pick on AKS for a moment — it’s the perfect example of shared responsibility confusion in action. Managed Kubernetes sounds magical: “Azure handles the hard stuff, we just deploy pods and watch the magic happen.”

Not quite. Think of AKS like a luxury car. Microsoft built it, keeps the engine running, and even installed the brakes. But you still need to steer, fill the tank, check the tire pressure, and make sure nobody left the keys in the ignition.

Here’s how responsibilities actually break down:

• Control plane: Managed, patched, and monitored by Azure, you can relax here.

• Worker nodes: Provided by Azure, but securing them is on you, patch, harden, and configure.

• Network: Azure gives you the virtual network and basic routing, but you define network policies, NSGs, and ingress/egress rules.

• Identity & Access: Azure provides Entra ID integration, but you’re responsible for RBAC, service accounts, and permissions.

• Container images: Azure hosts the registry options, but you need to scan, patch, and sign your images.

• Monitoring: Azure Monitor is available, but you must enable it, set alerts, and actually pay attention to what’s happening.

See the pattern? Azure gives you the platform, the plumbing, and the “suggestions,” but the knobs and switches are all yours.

Now, imagine someone deploys pods with default service accounts, leaves cluster endpoints public, or skips image scanning because “Azure handles that.” Boom - you’ve got an accidental data breach waiting to happen.

The moral of the story: managed doesn’t mean managed for you. AKS reduces operational overhead, but it doesn’t reduce responsibility. You still need to steer the ship, patch the containers, and ensure your workloads don’t accidentally broadcast themselves to the world.

Shared Responsibility in the Age of Zero Trust

Fast-forward to today’s world of Zero Trust and managed everything.
We’ve got serverless functions, AI APIs, and managed databases galore. Our responsibilities are shrinking in scope but growing in importance.

You may no longer patch Linux kernels but you’d better know who can invoke that Lambda function or access that Azure Key Vault. Identity and data security are the new battlefields.

Zero Trust doesn’t replace shared responsibility; it reinforces it. The trust boundaries are smaller, sharper, and constantly shifting. The only safe assumption is: trust no service, no account, and definitely no “default” setting.

Making It Work (Without Losing Your Mind)

So how do you keep your shared responsibilities from turning into shared confusion?

• Document everything. For each service, clearly define what’s yours and what’s the provider’s. A simple table works wonders.

• Automate the boring stuff. Use policy-as-code and IaC scanners (like Terraform’s Sentinel, OPA, or Azure Policy) to catch drift early.

• Turn on the lights. Logging, monitoring, Defender for Cloud, AWS Security Hub - use them. Visibility beats assumptions every time.

• Collaborate across teams. Security, DevOps, Developers and Leaders need to talk regularly. A five-minute conversation beats a five-hour post-mortem.

• Revisit responsibilities often. Every time you add a new cloud service, revisit your chart. Cloud evolves faster than org charts do.

Closing Thoughts – It’s Not Just a Model, It’s a Mindset

The shared responsibility model isn’t new. But the way we practice it needs a refresh.

It’s not a checklist. It’s a living agreement between you and your cloud provider.

The organisations that really get it don’t ask, “Who’s responsible for this?” they make sure someone always is.

Because in the cloud, responsibility may be shared, but accountability is not.