Helm charts may be the go-to tool for deploying Kubernetes apps quickly. But Microsoft warns that relying on default configurations could expose sensitive data and leave systems wide open.
Helm is a popular Kubernetes package manager. It helps developers bundle applications using YAML-based templates. These templates, called charts, speed up deployment across Kubernetes clusters.
However, security experts at Microsoft Defender for Cloud say that ease of use often comes at a cost. Their recent analysis found that many open-source Helm charts are misconfigured by default. That means critical services may be exposed to the internet without proper protection.
Michael Katchinskiy and Yossi Weizman from Microsoft explain that these out-of-the-box settings often lack basic safeguards. In some cases, they skip authentication entirely. In others, they allow public access to internal components. This can lead to serious data leaks or system breaches.
For example, Microsoft highlighted three real-world cases:
First, Apache Pinot exposes its main components—pinot-controller and pinot-broker—using a LoadBalancer. By default, there’s no authentication. That leaves data open to any attacker who finds the IP.
Next, Meshery, a service mesh tool, offers its dashboard through a public IP. Anyone with access can create a new user account. From there, they can launch pods and execute code inside the cluster.
Lastly, Selenium Grid uses a NodePort to expose services across all nodes. The only defense is the external firewall. If that’s weak, attackers can slip right through.
These examples show a troubling pattern. Developers often trust Helm charts to be secure by default. But many aren’t.
To reduce risk, Microsoft urges teams to inspect every chart before deploying. Review the YAML files. Limit external access. Enable authentication and role-based access controls. And don’t forget to monitor container activity for suspicious behavior.
It’s also smart to scan public interfaces regularly. Look for gaps in your security perimeter. Misconfigurations might go unnoticed—until it’s too late.
Many attacks on Kubernetes workloads start this way. A single weak default can open the door to a full-scale breach.
So while Helm charts make life easier, Microsoft’s message is clear: don’t rely on defaults. Build security into every step of your deployment pipeline.
