The Kubernetes orchestration platform is such a gigantic open source project that its evolution is inherently rapid. The pace of change significantly increases the importance of adhering to security best practices when using the ever-changing Kubernetes platform to automate deployment, scaling, and management of containerized cloud-native applications.
Ultimately, effective security also supports the entire Kubernetes project, since the technology's overall adoption depends on the confidence and trust that Kubernetes earns and establishes. That said, standard security procedures and practices that work well in traditional environments are often inadequate for securing Kubernetes environments, where traffic is vastly more dynamic, and where there must be security in place around the pods, containers, nodes, and images.
The correct security protocol depends on the specific nature of a deployment's infrastructure and patterns as well, which means DevOps teams must have a comprehensive understanding of these details. As you might imagine, this can complicate security efforts.
In a recent Cloud Native Computing Foundation (CNCF) survey, security stood as the top container-related challenge among organizations using Kubernetes. Achieving Kubernetes security calls for a thorough knowledge of the major risks that deployments face. Successful breaches can lead to data exposure and other systemic compromises that are easier to protect against than recover from.
Here are three dangers that put Kubernetes deployments at particularly high risk, and best practices for proactively defending against them.
Attackers can compromise containers or nodes with the intention of executing additional destructive actions within the environment that Kubernetes orchestrates. With a foothold in the controls of one container, attackers are often able to successfully escalate their privileges and allow themselves to spread the attack to other containers.
Best practices: When a container becomes exposed like this, it is crucial that administrators are already utilizing the capabilities built into Kubernetes that naturally restrict access across containers. This can be accomplished using network segmentation, namespaces, and operating system settings. Advanced segmentation using third-party network inspection tools such as container firewalls can provide additional protection. In this way, compromising a single container does not offer attackers or malicious programs the broader reach to affect other containers.
Attacks on Kubernetes services
These include strikes in which attackers threaten to access the system and bypass Kubernetes security controls, most often via the API server, the kubelet node agent, or other externally exposed means.
Best practices: Strengthen your deployment against attacks by exposing only the Kubernetes' services that are absolutely required. At the same time, make certain the security policies for those services that must be exposed are properly configured and authentication requirements are in place and effective.
Attacks from the inside (wrongful access) on Kubernetes controls
When malicious parties can get their hands on genuine Kubernetes administrative logins, they are enabled to do as much harm as their access allows.
Best practices: Implement tight access control, ensuring that users have only the privileges that they require. Access should also be limited by each user's job function and customized as much as possible to let users fulfill their duties while containing the damage that compromised credentials can do. In addition to limiting access, it is critical to analyze all user activity in order to swiftly recognize and remediate any harmful activities.
It's also worth noting that even rightful access can open the door to attackers if it is set up improperly (or unwatched). Strengthen systems to guard against techniques that exploit poor configurations and security gaps.
Approaching Kubernetes security from a broader perspective is the best way to accentuate these best practices. Achieving continuous network security throughout application development, deployment, and runtime—security that promotes effective access controls and minimizes attack surfaces—is essential to your organization's overall success as well as crucial to the security of the Kubernetes environment as a whole.