Building a Secure Container Registry Strategy

Container registries are a critical attack surface, but they’re often treated as simple storage.

Securing them doesn’t need to be complex or manual to be effective. With the right approach, container registry security reduces risk, improves reliability, and speeds up day-to-day operations. Here’s a practical strategy for securing your container registries.

Why You Need a Container Registry Security Strategy

Pulling images directly from public repositories like Docker Hub is the default for many teams. It’s fast, but it introduces significant risks – from availability issues (if the hub goes down, so do your builds) to supply chain blind spots (you can’t patch what you don’t control).

To mitigate these risks, we recommend a three-tiered approach to container registry security:

1. Leverage your cloud infrastructure: Use the native registry services available in the cloud you are currently using.
2. Centralize your products: Create private registries exclusively dedicated to storing and versioning your own products.
3. Implement intermediaries: Implement intermediate registries (or proxies) to store and cache the third-party product images you use. 

A Secure Container Registry Workflow in Practice

To visualize how this comes to life, let’s look at an example of a workflow that ensures only verified software reaches production.

1. CI/CD Pipeline: When a developer submits code, the continuous integration system generates the container image.
2. Private Registry: The image is sent to your private registry, acting as the "single source of truth".
3. Container Image Vulnerability Scanning: Automatically, the image is analyzed for known CVEs as soon as it is uploaded.
4. Blocking and Compliance: Instead of deploying blindly, tools like Kyverno enforce admission policies that block images not coming from trusted registries. Tools like Falco monitor runtime behaviour, detecting unauthorized images or anomalous activity before it becomes an incident.

The Benefits of a Secure Container Registry Strategy

Controlled registry management isn’t just an administrative task - it creates a more resilient and efficient engineering environment.

• Control and Availability: You own your uptime. By caching images locally, you insulate your business from external outages and rate limits. Even if there’s a service outage, your deployments continue.
• Cost and Speed: Caching also eliminates repetitive downloads from the open internet, drastically reducing bandwidth fees and deployment latency.
• Supply Chain Security: Strict registry rules prevent "typosquatting" attacks (like accidentally downloading ‘nignx’ instead of ‘nginx’) and stop unverified images from entering your pipeline.

Coming Soon: Automated Container Image Vulnerability Scanning

We’re extending our platform to include automated container registry security. Here’s what’s coming:

• Automated Image Discovery: Intruder integrates directly with your cloud (AWS, Azure, Google Cloud) to automatically discover container images as they’re uploaded, no complex setup required.
• Continuous Container Image Scanning: You’ll be able to add discovered images as targets for immediate vulnerability scanning. Images will be automatically re-scanned daily and when new versions are pushed, so you’re alerted quickly when new vulnerabilities are discovered.
• Low Noise, Clear Priorities: Intruder reduces noise and prioritizes issues based on risk, so you can focus on the vulnerabilities that most require your attention.

Security Doesn’t Stop at Deployment

Securing your container images is a huge win - it means you are stopping vulnerabilities before they ever leave the building. But security doesn't end at deployment.

Intruder keeps watch over your entire perimeter for new vulnerabilities and exposures, and continuously checks your cloud accounts for misconfigurations that could leave you vulnerable. Start a free trial to get started today.

Automated container registry security is coming soon to Intruder.