Affected: Go: helm.sh/helm/v3

A Helm contributor discovered an information disclosure vulnerability using the `getHostByName` template function.

### Impact

`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.

### Patches

The issue has been fixed in Helm 3.11.1.

### Workarounds

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.

### For more information

Helm's security policy is spelled out in detail in our [SECURITY](https://github.com/helm/community/blob/master/SECURITY.md) document.

### Credits

Disclosed by Philipp Stehle at SAP.