Microsoft has issued a warning about the growing security risks of using pre-configured Kubernetes deployment templates like Helm charts. While these out-of-the-box configurations simplify deployments, they often come at the cost of proper security controls, potentially leading to serious misconfigurations and data exposure.
According to Michael Katchinskiy and Yossi Weizman of Microsoft Defender for Cloud Research, the convenience of plug-and-play tools can result in Kubernetes applications being deployed with critical vulnerabilities. These flaws can expose sensitive data, open access to cloud environments, or even allow attackers full control of Kubernetes clusters.
Helm Charts: Convenience with a Hidden Cost
Helm, a widely used Kubernetes package manager, simplifies the process of packaging and deploying applications using YAML-based charts. These Helm charts are designed to be user-friendly and reduce complexity during setup. However, many open-source projects provide default manifests or templates that prioritize ease of use over security best practices.
Microsoft researchers noted two common issues in these default configurations:
- External service exposure: Applications are often exposed to the internet without proper network access controls.
- Missing authentication/authorization: Applications frequently lack built-in mechanisms to restrict access, leaving them vulnerable to unauthorized users.
These misconfigurations are not just theoretical. In the wild, real-world deployments using default Helm charts have led to critical vulnerabilities.
Real-World Examples of Risky Defaults
Microsoft highlighted several projects where these issues have been observed:
- Apache Pinot: By default, this OLAP datastore exposes its core services —
pinot-controllerandpinot-broker— via Kubernetes LoadBalancer services. These are accessible over the internet with no authentication, allowing unauthorized access to sensitive analytics data. - Meshery: This service mesh management tool exposes its user interface through an external IP. With no default access control, anyone with the IP can register as a user, interact with the interface, and deploy arbitrary workloads — potentially enabling code execution within the cluster.
- Selenium Grid: This testing tool uses a NodePort configuration that opens access across all Kubernetes nodes. Without additional firewall protections, this can provide external access to internal services, increasing the attack surface.
These examples underline the importance of not relying on default configurations when deploying applications in Kubernetes environments.
Security Best Practices for Helm and Kubernetes Deployments
To reduce the risk of misconfigurations, Microsoft recommends a proactive approach:
- Review default Helm charts before deployment. Don’t assume they follow security best practices.
- Restrict external access using Kubernetes network policies, firewalls, and ingress controllers.
- Implement authentication and authorization mechanisms for all exposed services.
- Continuously monitor running containers for signs of compromise or malicious activity.
- Perform regular scans of publicly accessible endpoints to identify vulnerabilities.
The warning is clear: default settings may be convenient, but they often leave environments wide open to attack. As Kubernetes adoption grows, so does the threat landscape, especially for organizations that prioritize speed over security.
Microsoft researchers concluded that many real-world exploits targeting containerized workloads begin with default configurations. Relying on ease-of-use templates without thorough security review can turn minor oversights into major security incidents.
Organizations must embrace a shift in mindset—security must be baked into the development and deployment pipeline, not added as an afterthought. As Kubernetes environments become more dynamic and complex, strict configuration hygiene is essential to protect cloud-native infrastructure.
