The 4 Cs of Cloud Native Security: A Simple Guide for DevOps Engineers

In this blog, we will look at the 4 Cs of cloud-native security.

We'll discuss essential concepts like least privilege, shift left, Software Composition Analysis (SCA), and Software Bill of Materials (SBOM) etc.

What Are the 4 Cs, and Why Should You Care?

The "4 Cs" of cloud-native security are

1. Code
2. Container
3. Cluster
4. Cloud.

This layered approach to security helps you think about protecting every level of your application, from your code to your entire cloud infrastructure.

According to a report by Gartner, spending on cloud infrastructure is soaring, and with it, so are the risks. By focusing on these 4 Cs, you can get ahead of those threats and secure your systems efficiently.

Shift Left for Better Security

Before we dive into the 4 Cs, let's quickly talk about Shift Left.

The idea here is to think about security from the very beginning of your development process. Shifting security practices to the left on your timeline.

It’s all about catching issues early, which saves you from bigger problems down the road. Imagine finding a security issue when you're just writing the code versus when the application is already live. It’s a lot easier (and cheaper) to fix it early.

This applies to all layers of the 4 Cs, starting with your code.

Let’s break down each of the 4 Cs with real-life examples.

🖥️ Code (app & IaC)

Your code is the heart of your application and Infra. It’s where everything starts. If your code has vulnerabilities, the entire security structure collapses. This is why it’s so important to think about security from the first line of code.

Here you need to understand the following concepts.

1. Software Composition Analysis (SCA): SCA tools help identify and manage open-source components and dependencies in your codebase. SCA scans the code to find known vulnerabilities in third-party libraries, ensuring that any code included does not have potential security risks. It also checks for license compliance issues.
2. Software Bill of Materials (SBOM):: An SBOM is a detailed list of all components, libraries, and dependencies that make up a software application. SBOMs provide a comprehensive inventory of all parts of the code, which helps in understanding the supply chain of the software. This allows organizations to quickly respond to new vulnerabilities as they can trace which components are affected.
3. Policy as Code: Automated checks for security rules in Infrastructure as Code (IaC) files, such as Terraform or Kubernetes manifests, ensure that no misconfigurations make their way into the deployment pipeline.

Lets look at an example.

Let's say you are developing an application and using third-party libraries to save time. But one of those libraries has a vulnerability, and now, your entire service is at risk. By implementing tools like Snyk for SCA to analyze and test code for vulnerabilities, you can avoid introducing risky dependencies.

Additionally, by taking an inventory of the software using Software Bill of Materials (SBOM) tools like Trivy and managing it centrally, you can ensure better control and oversight.

For example, the Log4j vulnerability (CVE-2021-44228) posed serious risks to countless applications that unknowingly used it as a dependency. In such situations, having an SBOM provides clear visibility into the components within your software, making it easier to identify if the affected library is part of your application and take quick action to mitigate the risk.

📦 Container

Once your code is written, it lives in a container. Containers are great for portability, but they also need their own security checks.

For example, many developers use a popular base image (e.g., node:latest, python:3.9) without considering that these images may contain vulnerabilities if not regularly updated. If an old image with known security flaws is used, attackers can exploit these weaknesses to gain unauthorized access or run malicious code in your environment.

Additionally, there are engineers who use publicly available images from random sources, which could potentially contain vulnerabilities

These mistakes can be avoided by following basic best practices, like using Hadolint or Trivy to audit your containers and making sure no sensitive data is baked into your images.

Enforcing these security checks in the image build pipelines ensures that images not following organizational security practices are not pushed into secured environments

Also, when it comes to containers running in production, most organizations aim to refresh or rebuild their containers on a monthly or bi-weekly basis to ensure they include the latest security patches

🗂️ Cluster

Clusters are where your containers run—think of Kubernetes or any orchestration platform you use. They need to be managed carefully because they tie everything together.

The Shadowserver Foundation has conducted an experiment that discovered 380 000 publicly accessible Kubernetes API servers.

How do you secure you cluster?

Let's say you are managing a Kubernetes cluster for a large-scale application. You set up a cluster without proper Role-Based Access Control (RBAC), meaning anyone with access to the cluster could do anything—including changing configurations and accessing secrets.

By enabling RBAC and enforcing strict network policies, you can create clear boundaries about who can do what, reducing the risk of malicious or accidental damage.

Also using tools like Kyverno or native pod admission controllers, you can create policies that block non-compliant pods and enforce security standards in your cluster.

☁️ Cloud

Finally, we have the cloud, which hosts everything else. This is where you need to think about identity and access management, data encryption, and all the security features your cloud provider offers.

For example, imagine you are hosting your entire infrastructure on AWS. You realize you have a bucket open to the internet by mistake. Unfortunately, this is more common than you'd think.

In fact, Gartner estimates that through 2025, 99% of cloud security failures will be the customer’s fault.

You can fix this by enabling Identity and Access Management (IAM) rules to strictly control who can access what, along with using tools like AWS Config or relevant cloud specific service to monitor for misconfigurations.

Putting It All Together: A Layered Approach

The beauty of the 4 Cs is that they layer on top of each other.

Each layer secures the one below it. If you secure your app/infra code, container, cluster, and cloud properly, you end up with a robust defense strategy that keeps threats at bay.

Each wall serves to protect the layer behind it, and if one wall is breached, the others are there to slow down the attacker. Defense in depth is key here, and that’s exactly what the 4 Cs provide.

A Quick Recap and Why It Matters

• Code: Secure it from the start.
• Container: Lock it down.
• Cluster: Control who can do what.
• Cloud: Use every security feature your provider gives you.

In today's cloud-native world, the stakes are high.

But with the 4 Cs as your guide, you can create a layered defense that gives you peace of mind. Remember, every step you take to secure one layer strengthens the whole.

So, whether you're writing that first line of code or setting up your cloud infrastructure, think about the 4 Cs and stay secure.

Now I would like to know your thoughts.

Comment below if have questions or insights to share!