What is Cloud Native Security? A comprehensive guide

1. Cloud

The Cloud layer is also known as the base layer, as it’s the foundation for all other layers. This is the infrastructure that runs your cloud services. 

This is the first layer you must go through before getting to any of the other layers. When this layer is weak (or misconfigured), the components built on top of this are not guaranteed to be secure.

Security at this layer will depend on managed or self-managed infrastructure. For managed infrastructure, think of infrastructure as a service (IaaS) from a cloud service provider (CSP) like Azure. With managed infrastructure, the cloud provider manages most of the security, but you still need to manage some.

Common security issues in the cloud layer occur in Identity Access Management (IAM). Examples include misconfigurations, such as improperly set permissions and overly permissive roles. Attackers can also exploit unsecured resources. Automated tools scan for these vulnerabilities and launch attacks.

2. Cluster

The cluster layer consists of Kubernetes components, including the worker nodes and the control plane. This is where you secure your Kubernetes workloads. Kubernetes uses encrypted communication channels like TLS (Transport Layer Security) to protect the data as it moves between components.

1. Components of the cluster

Securing configurable cluster components

• Controlling access to the Kubernetes API
  • Use Transport Layer Security (TLS) for all API traffic
  • API Authentication
  • API Authorisation
• Controlling access to the Kubelet
• Controlling the capabilities of a workload or user at runtime
  • Controlling what privileges containers run with
  • Limit resource usage on the cluster
  • Prevent containers from loading unwanted kernel modules
  • Restricting network access
  • Limit access to cloud metadata APIs
  • Control which nodes pods can access
• Protecting cluster components from compromise
  • Restrict access to etcd
  • Enable audit logging
  • Restrict access to alpha or beta features
  • Rotate infrastructure credentials frequently
  • Review third-party integrations before enabling them
  • Encrypt secrets at rest
  • Receiving alerts for security updates and reporting vulnerabilities

When you use Kubernetes, you have access to all the components underneath. But you are also more responsible for securing these components. There are many ways to secure them. Let’s have a look:

The most critical component of the cluster is the Kube API Server, which manages all communication within the cluster. Like the front door of your house, this is the main entry point of the cluster. With access to this, you get full control and can do anything.

Only admins and authenticated users can access this server. So, we must protect it. You can further protect it by implementing mutual TLS authentication and network access control lists to restrict access to trusted sources.

You should use role-based access control (RBAC) to limit access to cluster resources. It will ensure that only those who need permissions get them.

Also, Pod Security Admission should be enforced in Kubernetes to define security requirements for running pods and secure network policies to limit communication between different cluster parts. This will reduce the attack surface. Now let’s see how to secure applications running in the cluster.

2. Components in the cluster

Securing the applications running within the cluster:

• Role-Based Access Control (RBAC) Authorisation - (Access to the Kubernetes API)
• Authentication
• TLS for Kubernetes Ingress
• Application secrets management (and encrypting them in etcd at rest)
• Ensuring that pods adhere to specified Pod Security Standards
• Quality of Service (and Cluster resource management)
• Network Policies

As you can see, there is a difference between securing the components of the cluster and the applications running within it. 

Each requires different tools and approaches to protect your Cloud Native environment completely. Read about the 5 must haves for securing your AKS cluster security.

3. Container

Containers are a core part of Cloud Native architectures but must be secured. The container layer contains images that may have vulnerabilities you can scan for.

To secure your containers, ensure images are:

1. Vulnerability-free
2. Up to date
3. Managed throughout their life cycle

A common mistake is using images from unknown sources. Also, many fail to check for outdated or insecure configurations in the containers.

One tip is to ensure your images are from a trusted source. If you use public container images, ensure they are from a well-known, verified registry.

Also, don’t run containers with too much access or privilege. Containers should not be run as “root” or high-level access; this could expose your system to attacks if something goes wrong. Always run containers with limited permissions to keep the risk as low as possible.

Consider disallowing privileged users. Use a container runtime with better isolation for extra security. This could include using a distroless image. 

4. Code

The application code itself is one of the primary attack surfaces you control the most. In a “shared responsibility” model, the cloud service provider (CSP) is responsible for most of your infrastructure security (physical data centres, network, hypervisors etc.).

But as a user, you are responsible for your applications, data and configurations within the cloud environment.

Tips to implement security practices:

• Only access over TLS: Ensure you only use HTTPS for your app.
• Limit port ranges: Like restricting database access to only your IP address.
• Perform static code analysis: find weaknesses or bad coding practices in the source code itself.
• Regular patching: always stay updated on patches or updates for any open-source libraries you’re using, especially ones with security vulnerabilities.
• Dependency scanning: use tools to scan for vulnerabilities in third-party libraries before adding them to your codebase.
• Minimise your dependencies on open-source libraries: The more third-party code you use, the bigger your attack surface becomes and the greater the risk of vulnerabilities.
• Create an SBOM: Do this when using open-source libraries (very common in modern apps) as third-party components can have security issues. SBOMs help you identify components that developers have integrated directly into the application’s source code, as well as its dependencies. It gives you the visibility to detect potential security risks.

Benefits of Cloud Native Security

The benefits for business are great in productivity and operational efficiency. Here are the benefits:

✅Developer Productivity
Cloud Native security lets developers write and improve code, not infrastructure. Developers don’t have to worry about servers or platforms. That means faster, more efficient dev cycles. You can push code with quicker feedback loops and get real-time security feedback.

✅Operational Efficiency
Cloud Native lets you manage as code, so you don’t need big teams to run servers. That saves you money and scales. Cloud Native infrastructure means high availability and uptime. That means less downtime and more business continuity.

✅Security as a Speed Enabler
With Cloud Native security, developers can own the security process and fix issues now. That means better security and a faster development lifecycle. Instead of security being a gate or bottleneck, it’s a way to go faster as teams can push to production without delay.

✅Cost Reduction and Scalability
You can scale without big teams to run servers. Cloud Native security is automated and efficient. It lets you grow without the costs of traditional infrastructure, which required security appliances (e.g., firewalls), which added not only more costs but also complexity.

✅Continuous Security
Unlike traditional security, which is one-off, Cloud Native security is continuous. It means we constantly monitor and fix vulnerabilities and threats. This leads to a more resilient security posture.

The result is a system that lets businesses focus on their core goals - no longer worrying about managing the technical underlying infrastructure.

Security Challenges in Cloud Native Environments

Cloud Native architectures come with more scalability and agility but bring their own set of challenges in security:

Ephemeral and Dynamic Nature

Cloud Native introduces new security challenges because of its ephemeral and dynamic nature. Unlike traditional environments where applications run on long-lived virtual machines (VMs), Cloud Native environments (containers and serverless) involve more change. Containers come and go based on application updates or load and demand, so there is more environmental change.

Increased Complexity

Cloud Native applications are more vulnerable because of their complexity and scale. A traditional 3-tier app on a few VMs now includes hundreds of microservices. And all of them require security. Securing multiple layers, such as cloud, clusters, and code, is complex. A misconfiguration in any of these layers can be a vulnerability.

Increased Attack Surface

In Cloud Native applications, there is no single security perimeter. Instead, there are many loosely connected components, like microservices and containers. Each can be a way to attack or enter the system.

With more microservices and containers in production, the attack surface expands. Attackers can hit many parts of the architecture at the same time, making it harder to secure than a centralised system.

Traditional security tools based on perimeter models are no longer enough to protect this distributed architecture. In Cloud Native, every component (such as APIs, containers, and serverless functions) must be secured individually because there is no central defence.  
This decentralisation requires continuous security and automated, real-time threat detection.

Non-Secure Defaults

Containers, serverless functions, virtual machines, and Kubernetes clusters are not secure by default. They need to be configured with security before use.

A single misconfiguration, insecure container, or serverless function deployment can create serious vulnerabilities. This could lead to data breaches or system failures. You must monitor applications across all environments to ensure security configurations are set and maintained.

But the risks of human errors in the cloud will always be on the table. 

Dynamic Application Topologies

You can scale your application in the cloud from a couple of containers to hundreds, if not thousands, at any time. When you do that, you should consider securing your application as it scales up and down and changes shape, such as when you add new clusters.

Some of that must be done at the container image level. Think about securing the image. It must have no vulnerabilities, outdated libraries, or unused components.

Continuous Development and Deployment

The industry has moved to continuous development and deployment. This introduces more security challenges. With CI/CD pipelines, changes are constantly pushed to production, and there’s often not enough time for thorough security checks. This pace of change increases the risk of introducing vulnerabilities.

Shift to Developers

A big challenge in Cloud Native security is that developers are now responsible for securing apps. In traditional environments, the operations team handled updates and security patches. In Cloud Native environments, developers must create and update the container images.

Developers must be more aware of security flaws in their frameworks and libraries. Open-source components can mainly introduce vulnerabilities.

Cultural and Operational Changes

This is a bigger cultural and operational shift in how organisations approach security. In a Cloud Native world, security isn’t an afterthought or a final check before deployment.

This means a new mindset where security is built in at every stage of development, not just at the end. Developers, operators, and security teams need to work together.

Cloud Native security best practices

With more organisations migrating to Cloud Native environments, security approaches change.
 
Traditional security approaches work for on-premises systems. But, they often don't scale or adapt to the cloud's dynamic nature.

Here are some Cloud Native security best practices:

1. Shared Security Responsibility

You share the security responsibility with the cloud service providers. These (shared) responsibilities for managing infrastructure, platforms, and applications vary. It depends on which cloud service you use – IaaS, PaaS, or SaaS.

However, since a part of the responsibility is in hands of them, you are partly not in control. Traditional network-based or host-based security methods might also fall short. 

So, use your cloud provider's first-party tools to check for and fix security issues.

2. Shift Security Left

In Cloud Native environments, developers should integrate security early in the development lifecycle. This is also called "shifting security left." An example is vulnerability scans.

Adopt a DevSecOps approach. It requires the dev, ops, and security teams to work closely together. They must embed security practices into the entire software lifecycle. It is about preventing issues before they happen and not treating security as an afterthought or final step before deployment.

This means building all parts (code, containers, serverless functions, and infrastructure) with security at the top of your mind.

3. Automate Security

Automation is critical to keeping up with the fast pace of Cloud Native environments. Wherever possible, automate security tasks like vulnerability scanning and patch management. 

4. Securing Dependencies

Your app code likely has open-source dependencies. To secure them, we recommend using automated tools with complete vulnerability databases. You also need orchestration tools that trigger application security activities during development. Ensure these tools run continuously. They should detect and prevent vulnerable dependencies in containers or serverless functions that access your production environment.

5. API vulnerabilities

APIs are the backbone of Cloud Native apps. Weaknesses in API security can expose sensitive data or allow unauthorised access. So make sure APIs use HTTPS for secure communication to protect data in transit. The best way to secure APIs is to have stateless APIs. 

6. Leverage Security as Code

Security as Code is an approach where security configurations and policies are defined and managed as part of the codebase. This means consistent security configurations across all environments' development, stage or production. Infrastructure as Code (IaC) tools can automate the provisioning of secure cloud resources. This ensures that all deployed environments meet security standards without human intervention. Technology can enable the process so misconfigurations are reduced, and compliance is built in from the start.

Closing thoughts 

This article discussed how we must break security down into smaller tasks and embed it throughout development. Security architecture and testing should be continuous (and, where applicable, automatic).

Remember: Cloud Native security is an ongoing effort, not a one-time fix you apply at the end (like in traditional apps).

By implementing Cloud Native security measures, you can protect your Cloud Native apps and data from security risks and have a secure and compliant cloud environment.

We hope you’ve got a clearer view on this topic.