Medium · published February 8, 2023
Helm is a tool that streamlines installing and managing Kubernetes applications.`getHostByName` is a Helm template function introduced in Helm v3. The function is able to accept a hostname and return an IP address for that hostname. To get the IP address the function performs a DNS lookup. The DNS lookup happens when used with `helm install|upgrade|template` or when the Helm SDK is used to render a chart. Information passed into the chart can be disclosed to the DNS servers used to lookup the IP address. For example, a malicious chart could inject `getHostByName` into a chart in order to disclose values to a malicious DNS server. The issue has been fixed in Helm 3.11.1. Prior to using a chart with Helm verify the `getHostByName` function is not being used in a template to disclose any information you do not want passed to DNS servers.