Information disclosure in helm.sh/helm/v3

An information disclosure vulnerability exists in the getHostByName template function.

The function 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.