GHSA-pwcw-6f5g-gxf8 Helm vulnerable to information disclosure via getHostByName Function

• Go helm.sh/helm/v3: >= 3.0.0, < 3.11.1 → fixed in 3.11.1

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 document. Credits Disclosed by Philipp Stehle at SAP.