Growing Popularity of Kubernetes
Kubernetes (K8), an open-source platform, operates and oversees containerized applications and services across on-premises and various cloud environments, including public, private and hybrid clouds. It streamlines intricate processes throughout the container's life cycle, such as provisioning, deployment, networking, scaling, load balancing and more. As per the CNCF annual survey1, in 2023, 66% of potential/actual consumers were using Kubernetes in production and 18% were evaluating it.
Despite widespread adoption and growing popularity, Kubernetes usage has many security challenges. A recent survey2 indicates that two-thirds of organizations have delayed or slowed down deployments due to security concerns associated with Kubernetes.
In this blog, let's explore some key K8-related security challenges DevSecOps professionals face and some best practices to mitigate the risks.
Kubernetes Security Challenges
Securing Container Images
Kubernetes allows you to run your workloads without the complexity of managing underlying machines, autoscaling or configuration management. However, a workload containing security vulnerabilities can weaken the system and make it susceptible to malicious attacks. Therefore, it's crucial to source images from trusted providers and consistently use updated images.
Cluster Misconfigurations
Misconfigurations in Kubernetes clusters are among the most frequent security threats. Even minor errors in configuration settings can create significant vulnerabilities, making clusters susceptible to cybercriminals’ attacks.
Secrets Management
Kubernetes secrets are sensitive information like SSH keys, passwords or authentication tokens. Storing secrets in plain text within container images or pod configurations poses a significant risk as attackers can easily compromise these and gain access to systems with those credentials.
Compliance Management
Achieving and maintaining regulatory compliance is a key priority for organizations. However, managing compliance in cloud-native environments is a highly challenging endeavor. Organizations must implement multiple security measures, including enforcing best practices, benchmarks, industry standards and internal organizational policies.
Beyond maintaining regular compliance, organizations must also provide proof of compliance. This necessitates visibility, monitoring and logging to gather the data required for audits. To provide auditors with easier accessibility to the necessary data or systems, organizations need robust features that are usually unavailable in open-source Kubernetes.
Lack of Visibility
Gaining visibility is a huge challenge, especially in complex, distributed and containerized environments. When several containers are scheduled, deployed and terminated, each one needs to be tracked, monitored and managed. The highly dynamic nature of containerized workloads makes it difficult to collect, track and understand relevant metrics.
One can deploy Kubernetes in multi-cloud or hybrid-cloud environments. Each cloud vendor provides monitoring and visibility tools and getting in-depth visibility across environments becomes a challenge.
How Can You Secure Your Kubernetes Environment?
We want to share some best practices for implementing security in your Kubernetes clusters.
Container Image Scanning
Verifying that container images are free of vulnerabilities is crucial, as every container created from an image inherits its vulnerabilities. This is typically achieved by scanning the base image and all associated packages against a vulnerability database. You must scan images at all stages of the CI/CD pipeline and access to image registries must be controlled to mitigate pipeline misuse.
Harden Kubernetes Clusters
The Kubernetes cluster configuration is not secure by default. To maintain the security of your clusters, you need to review the current configuration, identify gaps and apply remediation measures. It’s also important to scan your clusters for compliance with benchmarks like the CIS Benchmark for Kubernetes. You can build a trust model for each component of your cluster by identifying probable threats and specifying how the cluster will respond to and mitigate each threat.
Enable Role-based Access Control (RBAC)
Role-based access control (RBAC) in Kubernetes is crucial for managing permissions and ensuring that only authorized individuals can access specific information. Implementing strict RBAC policies helps mitigate the risks associated with unauthorized access. Improper permissions management can lead to potential data breaches, where sensitive information might be accessed or leaked by those without proper authorization. RBAC in Kubernetes is a sophisticated framework that regulates access to the Kubernetes API more granular control over who can access specific resources and what actions they can perform. With an additional layer of control, RBAC can help minimize the potential impact of malicious or accidental actions.
Continuously Upgrade
Since tracking all potential attack vectors for your cluster is challenging, the best defense is to always run the latest version of Kubernetes. Kubernetes maintains release branches for the most recent three minor releases. Additionally, depending on severity and feasibility, it recovers any applicable security fixes to those releases. Patch releases are cut from those branches at a regular cadence, plus additional urgent releases when required. Hence, it’s recommended to upgrade your Kubernetes cluster to the latest available version.
Secure Kubernetes Secrets
Secrets should be mounted into read-only volumes in your containers rather than exposed as environment variables. Additionally, secrets should be kept separate from an image or pod. Even if a pod cannot access the secrets of another pod, anyone with access to the image would have access to the secret as well. Also, it’s recommended to encrypt your secrets using a meticulous backup and encryption solution and when possible, utilize full disk encryption.
How Can Kubernetes Security Posture Management (KSPM) Help?
Kubernetes Security Posture Management uses automation to locate and fix security, configuration and compliance issues that affect Kubernetes components. It’s an extensive set of tools that warn operators about security and compliance issues that are likely to go unnoticed during manual audits.
Although different tools may handle Kubernetes Security Posture Management (KSPM) differently, workflows will have fundamental components.
Define Security Policies
KSPM tools are typically driven by pre-built policies specifying compliance and security risks. However, administrators can create their own. For instance, to uphold the principle of least privilege and remove any access privileges for inactive users, you can build RBAC policies. As a result, Kubernetes Security Posture Management will discover any RBAC misconfigurations linked to unauthorized entry requests from potential hackers.
Scan Configuration
The KSPM tools can automatically scan a Kubernetes environment using security and compliance benchmarks. For each resource they assess, they look for configurations that differ from the benchmarks defined by the security and compliance team or standard regulatory benchmarks like CIS, PCI DSS, SOC2, HIPAA etc. For instance, you can use KSPM to check RBAC policy violations such as compromised service accounts that don’t follow the least privileged access principle or inactive accounts from previous employees who have left the firm.
Analyze and Alert
When the KSPM tool finds a policy violation, it can typically assess its severity and if required, publish an alert or notification. In addition, it can provide remediation guidance to help remediate the policy violation.
Using Chef for Kubernetes Security Posture Management
Progress Chef Cloud Security solution provides Kubernetes Security Posture Management capabilities to protect Kubernetes elements like pods, network policies, container network interfaces (CNI) and secrets.
Progress Chef InSpec is the engine behind Chef Container Security, and it functions as a framework to test and audit your applications and infrastructure. It compares your system's actual state with the desired state using easy-to-read and easy-to-write code. With the policy-as-code approach, it is easy for users to create or customize policy definitions or even use standard benchmarks provided by Chef, like the CIS Kubernetes benchmark.
Hence, you can use the same workflow and processes to assess the security posture of any container environment. Chef maintains and keeps adding to an exhaustive library of premium content of profiles and resources. Besides KSPM, Chef provides resources and profiles to secure your Docker, OpenShift and Podman environments. Using the CIS Kubernetes Benchmark, you can continuously assess the security posture of your Kubernetes clusters.
Find out more about how Chef Cloud Security can secure your container and cloud environments by visiting our various resources:
To learn more about securing your Kubernetes environment, contact us today!
References:
https://www.redhat.com/en/resources/kubernetes-adoption-security-market-trends-overview
