Top 7 Kubernetes Security Best Practices

Kubernetes Security VS Application security Best practices

In many cases, Kubernetes security best practices align with general network and application security best practices. For example, encryption of data at rest and transit is table stakes in any production environment – K8s or otherwise. Similarly, proper handling of sensitive data such as passwords and API keys is a must. For the most part, enterprise DevSecOps teams are aware of these basic best practices and do a good job leveraging them.

Here, we’ll go beyond the basics and look at 7 Kubernetes security best practices that can take enterprise security to the next level. 

#1. Make K8s Posture Management & Visibility A Priority 

At a high level, K8s posture management and visibility is about being able to do two things effectively:

• Configure all K8s clusters and container workloads securely. 
• Have continuous granular visibility into all the workloads and configurations within the enterprise. 

Of course, achieving these goals is easier said than done, particularly in multi-cloud environments. So, what specifically can enterprise security teams do to optimize their Kubernetes security posture and visibility? We’ll cover many of those steps in the following best practices. However, a prerequisite is organizational buy-in to prioritize K8s security across the enterprise. 

Here are some of the most impactful steps that enterprises can take to begin their journey to improve K8s security at a high level. 

• Mandate configuration of Kubernetes clusters using industry best practices: While every deployment has nuance, all enterprises can reference well-defined container security standards to harden their K8s clusters and container workloads. For example, NIST 800-190 Application Container Security Guide (PDF) and CIS benchmarks provide expert guidance and are excellent baselines for enterprises to follow. Leveraging standards like these can go a long way in improving overall enterprise security posture. 

• “Shift left” and automate: Manual configuration is a recipe for oversights and human error. “Shift left security”, the process of integrating security as early in the development process as possible, inherently helps limit manual configuration and encourages automation of security best practices. As a result, DevSecOps teams can build security best practices for Kubernetes into CI/CD pipelines to ensure they are applied consistently and scale seamlessly. 

• Implement micro-segmentation: Micro-segmentation of containers and Kubernetes clusters helps enforce zero-trust principles across enterprise infrastructure and limits lateral movement in the event of a breach. As a result, implementing micro-segmentation policies across enterprise workloads is critical for optimizing overall security posture. 

• Enforce correct annotation and labeling across the enterprise: Kubernetes labels dictate how policies and objects are grouped and even where workloads are deployed. As a result, ensuring consistent labeling is used across enterprise clusters is an essential aspect of maintaining a strong security posture. Similarly, enforcing policies requiring specific annotations on workloads and specifying taints and tolerations to limit where workloads can be deployed are necessary tactical steps for DevSecOps teams. 
• Leverage continuous monitoring: Point-in-time security audits, pen tests, and vulnerability scans are no longer enough. To keep up with constantly iterating threats and network perimeters, enterprises must continuously monitor and scan for threats, intrusions, and insecure configurations across their K8s clusters. 

#2. Implement Image Assurance

Container images are the building blocks of K8s workloads. Unfortunately, insecure container images are a widespread threat. Case in point: a 2020 analysis found that over half of the images on Docker Hub had a critical vulnerability. As a result, ensuring the images used in a K8s cluster are secure and pulled from trusted sources are important Kubernetes security best practices. 

To implement image assurance enterprises should leverage security tooling that:

• Scans images during development and runtime.
• Prevents deployment of containers that don’t adhere to policy.
• Deconstructs image layers and scans packages and dependencies within an image.
• Checks images for malware, vulnerabilities, and insecure configurations like passwords and encryption keys in plaintext.

#3. Fine-tune Policies With Admission Controllers

The Kubernetes API server is an attack surface that enterprises must protect against insecure or malicious requests. Admission controllers are pieces of code designed to help do just that. 

Admission controllers act on API calls after authorization, but before persistence, so they can help safeguard against cluster modifications in the event of human error, misconfigurations, or compromised accounts. With admission controllers, enterprises can define fine-tuned policies to limit a variety of actions including pod updates, image deployments, and role assignments. 

#4. Protect Web Apps And APIs With a WAAP

Traditional web application firewalls (WAFs) and intrusion detection and prevention systems (IDS/IPS) aren’t flexible or intelligent enough to keep up with the threats facing modern web apps and APIs. To address threats such as bots and zero day attacks, enterprises should use a Web Application and API protection (WAAP) solution. 

WAAPs are designed with modern cloud-native applications in mind and provide functionality such as:

• API and microservice protection.
• Built-in Next-Generation Web Application Firewall (NGWAF).
• Bot and DDoS protection.
• Advanced rate limiting that reduces false positives.

#5. Use Intelligent Runtime Protection Solutions 

One of the toughest balancing acts with K8s security is identifying malicious behavior and protecting workloads from real-time attacks while limiting false positives. To get the balancing act right, enterprises need intelligent solutions that use multiple data points to identify and mitigate threats. This requires a three-pronged approach to runtime protection that includes:

• Runtime profiling: Every K8s cluster is different, and performance baselines are important for detecting malicious behavior. Modern runtime protection solutions perform runtime profiling to establish baselines of normal behavior for network flows, filesystem activity, and running processes. These baselines can help threat detection engines detect and mitigate potential threats with context, improving overall security posture and limiting false positives. 

• Malicious behavior signature detection: A robust database of known malicious behavior enables security tooling to quickly and accurately detect common threats. By comparing observed behavior to a signature database, well-known threats can be contained before they have the opportunity to breach a network. 
• Anti-malware engines: Intelligent anti-malware engines and continuous scanning of workloads at runtime are critical components of runtime protection. Anti-malware engines are the workhorse of runtime security and enterprises should continuously scan all workloads to detect threats as soon as possible.  

#6. Invest In Modern K8s Intrusion Protection

IPS/IDS technology has been a staple of enterprise security for years, and that hasn’t changed with the rise of containers and Kubernetes. Fundamentally, tooling that detects suspicious behavior and flags or prevents it will always be a cornerstone of enterprise security. What has changed is the dynamic nature of the assets IPS/IDS must protect and the threats facing modern enterprises. 

Modern intrusion protection solutions for Kubernetes need to be able to perform functions such as:

• Internal port scanning from K8s pods.
• Analyze data related to accounts, application traffic flow, and K8s cluster operations. 
• Detect modern threats like crypto-mining. 

Additionally, modern IPS/IDS need to operate in multi-cloud environments to protect K8s clusters wherever they are deployed. 

#7. Emphasize Visualization And Regular Reporting

To understand the current state of their security posture, enterprises must have access to up-to-date reports and visualizations (e.g. dashboards) that account for their entire application infrastructure. 

There’s no one-size-fits-all set of KPIs and reports all enterprises need, so customization is an important aspect of an effective solution. However, any enterprise-grade K8s security visualization and reporting solution should include aggregated data from across all clouds, the ability to drill down to show more granular detail, and a single pane of glass overview of assets and alerts.

It’s important not to overlook the importance of dashboards and high-level overviews when evaluating visualization and reporting tooling. One of the biggest challenges of many reporting tools is information overload and lack of clarity. There is so much information it becomes incoherent at an enterprise level. With the right high-level visualizations and reports, enterprises can quickly and effectively assess their overall container security posture and understand which findings they need to focus on first.