Summary
A Helm contributor discovered an information disclosure vulnerability using the getHostByName template function.
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.
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.
CVE-2023-25165 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.11.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The issue has been fixed in Helm 3.11.1.
Frequently Asked Questions
- What is CVE-2023-25165? CVE-2023-25165 is a medium-severity security vulnerability in helm.sh/helm/v3 (go), affecting versions >= 3.0.0, < 3.11.1. It is fixed in 3.11.1.
- How severe is CVE-2023-25165? CVE-2023-25165 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of helm.sh/helm/v3 are affected by CVE-2023-25165? helm.sh/helm/v3 (go) versions >= 3.0.0, < 3.11.1 is affected.
- Is there a fix for CVE-2023-25165? Yes. CVE-2023-25165 is fixed in 3.11.1. Upgrade to this version or later.
- Is CVE-2023-25165 exploitable, and should I be worried? Whether CVE-2023-25165 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-25165 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-25165? Upgrade
helm.sh/helm/v3to 3.11.1 or later.