In computer science, a “container” is essentially a stripped-down version of a virtual machine that consequently has a smaller footprint. It’s an effective solution to achieve reliability when software environments change, and it’s gained momentum in the last few years. Because of this, it’s important to apply security concepts to applications which run on such containers.
The model, however, is not simple to develop and execute, and this is a problem because software security is a daunting task. Even though containers are supposed to act like reduced versions of VMs, the environments have many different layers and tools necessary in their production settings, thus complicating the scenarios. Nevertheless, there are effective ways to increase container security.
Why are containers necessary?
Before understanding the importance of securing containers, it is necessary for developers to understand why these environments are important in the first place. Any software programmer can relate to cases where an application works perfectly in the developer’s machine, only to be riddled with problems once it’s moved to production.
The reason why this occurs is that runtime conditions are not the same. To solve the issue, an ideal atmosphere for the application is one where all dependencies, configuration files, libraries, etc. are bundled into a single package, thus eliminating the differences in operating system distribution and other infrastructure. This simplification allows programmers to control elements that can cause problems. Thanks to these benefits, companies like Microsoft have embraced containers in platforms like Azure and Visual Studio.
Containers create different layers such as images, registries, orchestrators, and microservices. These are generated by the service to control the software environment. However, this also sets up elements which may be vulnerable to attacks. Therefore, security must include a way to protect hosts from intruders. As the idea has evolved in the last few years, developers have worked on enhancements to protect containers. One such notion is the use of a signing infrastructure: when images are signed, this prevents launching unauthorized or untrusted containers.
However, the most sensitive aspect of the environment which requires protection is the operating system level. After all, vulnerabilities in this layer can provide intruders with complete access to the stack. The container runtime and registry are two additional layers that security experts need to address. While the OS is the easiest to secure, the container runtime is generally harder because of the difficulty in monitoring. However, some tools to handle this type of security.
The registry and container images have a security overlap because registries are fundamental for images and depend on these for their existence. The orchestrator, which is the central part of the container, handles how the application runs and provides provisioning services. These can become a liability if left unsecured. Given the different layers and the difficulty of handling security, it is best to look for third-party solutions that are built specifically to increase the security of the environment.
As security continues to be a concern, companies have focused their efforts on creating innovative techniques that directly address the problems. For example, developments allow container security scanning that informs administrators if images have security vulnerabilities. Some solutions provide runtime defense, which enforces security models while also using cloud-native firewalls, among other measures. These types of solutions offer clients software that can profile the expected behavior of processes and activities and can flag others that look to have unexpected behavior or malicious practices. When looking for solutions, ensure the product addresses the different areas of security concerns to ensure that their use does not add unintended weaknesses.