How to tackle Container Security?
- Aman Bansal
- Sep 30
- 5 min read
Containers are everywhere in modern app development. They’ve become one of the fastest and most convenient ways to build, package, and ship software. Why? Because they’re lightweight, portable, and scale effortlessly, which makes them perfect for today’s fast-moving teams.
Think about companies like Netflix or JioCinema (a leading streaming service in India). How do they deliver seamless video content to millions (if not billions) of users with minimal downtime and excellent performance? The answer is containerized applications, designed to scale, recover, and deploy across distributed environments without worrying about the underlying infrastructure.
However, with all its benefits, it also presents a new set of security challenges that traditional security approaches struggle to handle.
In most organizations, containers appear faster than security teams can keep track of them. Developers pull up images, CI/CD pipelines push code to run on container images, and workloads run across hybrid or multi-cloud clusters, often without the security team having full visibility. It leads to Shadow containers, insecure images, misconfigured Kubernetes deployments, and a growing attack surface.
If you're a security expert focused on container protection, this blog shares practical insights on establishing a robust container security program within your organization to safeguard your containerized applications without slowing down your development.
Container Lifecycle:
Getting the Base Image
Use trusted source to get the base images(DockerHub)
Use verified images from trusted registries.
Store in local registry
Ex: Use ECR or Artifactory for storage
Use signed images to prevent tampering.
Enable vulnerability scanning in the registry.
Build & Test
Integrate SAST, dependency scanning, and secret detection.
Avoid running containers as root.
Keep Dockerfiles minimal and secure.
Deployment
Use admission controllers or policies (OPA Gatekeeper, Kyverno).
Restrict deployments to approved registries/namespaces.
Apply Kubernetes PodSecurity or equivalent controls.
Run & Monitor
Apply least privilege (capabilities, seccomp, AppArmor).
Monitor with eBPF/Falco for anomaly detection.
Track container network traffic and syscalls.
I’ve seen organizations of all sizes struggle with container lifecycle management. Too often, critical steps are skipped or applied inconsistently, leaving thousands of vulnerabilities to pile up inside containers. The result is not just weaker security, but a slowdown of the entire security program. A big reason for this gap is ownership: different phases of the container lifecycle fall under different teams — DevOps, engineering, and security. Without clear collaboration and alignment on best practices, security controls end up being applied too late, or sometimes not at all.
Build Container Security Program
To build any security program, collaboration is key. In the case of containers, DevOps, infrastructure, engineering, and security teams must work together to define clear processes. A strong program takes a structured, maturity-driven approach that blends technology, process, and ownership. It starts with governance: deciding which base images can be used, how registries are configured, and who approves security exceptions. For regulated industries, these policies should align with compliance standards such as PCI DSS, CIS Benchmarks, or NIST guidelines.
The first step is securing your base images and storing them in a trusted local registry such as Artifactory or Amazon ECR. While DevOps or infrastructure teams typically own this process, ownership must be clearly defined no matter where it sits. Images should always be tagged correctly in the local registry (for example, the most recent version tagged as latest), and automation should be used to regularly pull updated images from trusted sources.
Continuous vulnerability scanning for base images is critical. Here, security and DevOps teams work hand in hand on configurations to detect whether an image source needs to be replaced due to excessive vulnerabilities. Tools like Snyk’s vulnerability database provide up-to-date reports on Docker image versions, helping teams choose the most stable and secure baseline. There are also vendors such as Chainguard and Root.io that offer pre-hardened, vulnerability-free container images, a good option if you’d rather avoid managing images in-house.
Once you move into the Build and Test phase, CI/CD integration becomes essential. Even secure base images can accumulate new risks if outdated or vulnerable packages are installed on top. Embedding container scanning in your pipelines ensures these issues are caught early. GitLab’s built-in scanning templates, for instance, integrate smoothly into CI/CD workflows and provide visibility into vulnerabilities before code is deployed.
Autopatch your Base Images: Patching base images isn’t as complicated as it may seem. Think of it the same way you update local libraries on your operating system -- a simple command refreshes packages and applies the latest patches. The same approach works for containers: regularly updating your base images ensures the most vulnerable packages and libraries are addressed.
yum update all -y
OR
apt-get update && apt-get upgrade -y Create a schedule pipeline to trigger a workflow:
Continuous scanning of the container Images: Container security doesn’t stop once an image is built — vulnerabilities are discovered every day, which makes continuous scanning essential. Tools like Wiz provide automated, ongoing scans of deployed container images, helping teams quickly identify new risks.
A common debate is whether security teams should limit scanning to containers running in production or broaden it to all images across environments. In practice, it’s best to cover both: production workloads demand the highest priority, but scanning non-production images early helps reduce risk before they ever reach prod.
For organizations that prefer open source, there are several free scanners available. You can even combine multiple scanners into a custom script to add another layer of assurance. The key takeaway is simple: ensure continuous vulnerability scanning is always in place, regardless of the tools you choose.
Best Security Practices Related to Root Access: By default, many containers run processes as the root user inside the container. While this might feel “isolated” from the host, it still carries serious risks: If an attacker exploits a vulnerability inside the container, root access could allow them to break out into the host system (container escape). Some of the best practices:
Default Behaviour: Always configure containers to run as a dedicated, non-privileged user.
Use rootless container runtimes: Technologies like Rootless Docker or Podman let you run containers without requiring root privileges on the host.
Avoid --privileged Mode: --privileged gives the container full access to host devices and capabilities.
Read-Only File System: Run containers with a read-only root filesystem (--read-only) where possible.
If you are using AWS, the SecurityHub Service is great to have to find the above misconfigurations in your AWS-hosted container environment.
Container Runtime Detection: Container runtime security focuses on protecting applications while they are running. Even if an image is clean at build time, new vulnerabilities, misconfigurations, or malicious activity can emerge once containers are deployed. Robust runtime security ensures applications continue to operate securely and remain protected against active threats.
This can be achieved using EDR solutions such as CrowdStrike, which monitor activity at the host or container level to detect anomalies, privilege escalations, or suspicious processes. In addition, container-native runtime detection tools (like Falco or Sysdig) can provide deeper visibility into container behavior, helping security teams catch threats that traditional host-based tools might miss.
All the controls discussed above focus on prevention, but responsive security controls are just as important to secure your container environment.
Vulnerability Management Process: Even with strong preventive measures, vulnerabilities in containers are inevitable. That’s why container-related findings must be integrated into the organization’s overall vulnerability management program. Regularly rotating and updating base images helps, but new CVEs will continue to emerge. Security teams need to track these vulnerabilities, triage them effectively, and remediate them within defined SLA timelines.
The controls outlined here provide a solid foundation for securing containers and building a container security program. But success depends on more than tools and processes - it requires a shared responsibility model across DevOps, security, and engineering teams. Without this collaboration, even the most well-designed, cloud-focused security programs will struggle to succeed.
References:
Comments