Containers are software packages that contain all of the elements they need to operate on any system, including an operating system, so they can run as well on a public server as on a private computer or even on the cloud. Containerization can make it easy to deploy software applications across a range of computing environments, but container security is essential for keeping containerized networks safe from malware, viruses, and cyber attacks.
Like any technology, containerization isn’t foolproof. The technology has its flaws, and it can be easy to make mistakes with this technology that compromise its security. Here are some of the most common container security mistakes so you can avoid them.
Giving Too Much Privilege
When containers are too privileged, hackers can use that access system resources that the container has access to, even if it shouldn’t or doesn’t need to. Keep application privilege in check using the principle of least privilege. Otherwise, giving a container privileges it doesn’t need can threaten the security of the container and the security of the host environment. Internal host security cannot protect against exploitation of privilege in a container. Privileges should be given out sparingly and they should be drilled down to the most granular levels possible. Do not give containers broad permissions – this makes them a threat to the security of the host environment.
Forgetting External Security
It’s easy to focus all your energy on best security practices for the container itself, and forget to prioritize the security of the host machine or environment. Just as host security cannot protect the host from a compromised container, container security cannot protect the container from a compromised host. It’s essential to keep both host and container secure in order to ensure security for both. Secure your host machine or cloud environment and the network they’re operating on against all traditional threats.
Allowing Overexposure
A container that is exposed to a public network needs the right container security to withstand that kind of exposure. The principle of least privilege should be applied here, too. Do not expose a container on a public network to all kinds of attacks by giving it sweeping permissions. Open it only to those channels that are necessary.
Otherwise, container processes and permissions could be hijacked and exploited to steal data within the container as well as compromise the host system. Commands designed to be run within a container should always be run without permissions whenever possible, to keep privileges from escalating inside the container environment. Consider, too, that the network on which the container host operates should also be secured against threats.
Not Using an Immutable Image
Containers should always be built on immutable images. Immutable images never change – they have stability and integrity that can increase security. Immutability makes deployments safer and makes sure they happen the same way every time. There should be no updates, patches, or changes to the container configuration. If you need to update the container, you should build and redeploy a brand new image. To do otherwise would compromise container integrity, and leave the door open for malicious actors to come in and contaminate the container with malicious code. Changes to containers should be made in test environments, carefully tested, and approved before they’re deployed as replacement immutable images.
Trusting Code Libraries
Code libraries are pre-written modules of code that programmers can use in building a container to make it perform certain processes. Generally, programmers use code libraries so they don’t have to write out brand new code for every single mundane function that has already been hashed out. But it’s a mistake to assume these code libraries don’t have malicious code in them, and you shouldn’t include a code library in your container unless you’re sure it’s safe. Development-suite as well as third-party libraries can contain vulnerabilities that could put your container and host system at risk.
Always scan code libraries for vulnerabilities, and only use what you absolutely need to build out container processes. You should definitely take extra care inspecting third-party libraries for security vulnerabilities. A strong, formal architecture review process can protect your containers and their host systems from vulnerabilities built into code libraries.
Containerization can really make it a lot easier to deploy apps across different computing environments, but as with any computing technology, security is paramount. Know how to avoid the most common container security mistakes most cybersecurity professionals make, so you protect your data, your devices, and your whole network.
