Docker Security Risks: Main Threats in Containerized Applications and How to Fix Them

Have you ever created a fun project involving Docker, sat back and thought, "this is easy!"? Later, you realized there is a possibility of one tiny mistake can result in things becoming tangled and your deploy ruined? Yes, levels of comfort with the container concept can become outright dangerous is compromised as well. Let's talk briefly about brewery security issue concept at a high level.

The Shared Kernel Problem​

All containers residing on a host share the exact kernel. So, if someone eventually successfully hacked into a container, you now given if your entire server!

One time, I was experimenting with a container on my system, but I eventually ended up breaking into system files, in which I should never had access to at all, and I learned "containers are not actually virtual machines," and I need to be careful.

Tip: Always keep your host OS up to date, and consider using something like SELinux or AppArmor to prevent doing anything risky.

Untrusted Images and Registries​

Most users continue to download random images from Docker Hub, since it is easy and quick to work. While an image could just be old, if you don't trust the image and it happens to contain malware, that is a major problem for your distribution. Store in a secure way:

• Scan your images with tools like Trivy or Clair.
• Only use sources you trust or are official.
• Consistently updated images to remove any old vulnerability.

Incorrect Container Settings​

Containers require little work to allow them to run, therefore many beginners run containers as root. This means that if a hacker gets in, they would also have root access to run any commands to destroy things.

Instead:

• Execute containers as a non-root user.
• Use --cap-drop to drop unneeded permissions.
• Implement limits on CPU and memory to defend against Denial of Service attacks.

Weak Networking Configuration​

Containers communicate with each other over virtual network interfaces. If you do not effectively isolate them, an attacker can take over or snoop on the other containers.

You should establish network policies to define who can connect to who, and make sure you implement TLS to provide encryption of your data in transit.

In Summary​

No doubt, containers provide rapid development speed, however, we must still make sure they maintain security and are patched. Think of containers as small servers - they need protection and we need to check on them continuously. Next time you interact with Docker, you should ask yourself: Is this configuration secure? One vulnerable container can result in a security incident that can cause serious problems.