CVE-2020-11013 is a medium-severity (CVSS 5) Information Exposure vulnerability in helm.sh/helm/v3. 1 public exploit reference exists, so weaponization risk is real. A fix is available for helm.sh/helm/v3 — see the affected versions and patch details below.
Lookup function information discolosure in helm
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-11013 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
helm.sh/helm/v3Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
The Helm core maintainers have identified an information disclosure vulnerability in Helm 3.0.0-3.1.2.
Impact
lookup is a Helm template function introduced in Helm v3. It is able to lookup resources in the cluster to check for the existence of specific resources and get details about them. This can be used as part of the process to render templates.
The documented behavior of helm template states that it does not attach to a remote cluster. However, as the recently added lookup template function circumvents this restriction and connects to the cluster even during helm template and helm install|update|delete|rollback --dry-run. The user is not notified of this behavior.
Running helm template should not make calls to a cluster. This is different from install, which is presumed to have access to a cluster in order to load resources into Kubernetes. Helm 2 is unaffected by this vulnerability.
A malicious chart author could inject a lookup into a chart that, when rendered through helm template, performs unannounced lookups against the cluster a user's KUBECONFIG file points to. This information can then be disclosed via the output of helm template.
Patches
This issue has been fixed in Helm 3.2.0
Workarounds
Due to another bug (also fixed in Helm 3.2.0), the command helm lint will fail with an error if the lookup function is used in a chart. Therefore, run helm lint on an untrusted chart before running helm template.
Alternately, setting the KUBECONFIG environment variable to point to an empty Kubernetes configuration file will prevent unintended network connections.
Finally, a chart may be manually analyzed for the presence of a lookup function in any file in the templates/ directory.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Helm repository
- For security-specific issues, email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | helm.sh/helm/v3 | ≥ 3.0.0&&< 3.1.3 | 3.1.3go get helm.sh/helm/v3@v3.1.3 |
Affected Products
helmhelmResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for helm.sh/helm/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update helm.sh/helm/v3 to 3.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-11013 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Three mitigations are described in the Helm project's advisory. Running `helm lint` will report an error if a template uses the lookup function; thus templates that pass `helm lint` can be used safely without triggering this vulnerability. Setting `KUBECONFIG` to point to an empty kubernetes configuration file will prevent unintended network connections. Manually analysing charts to ensure there is no use of the `lookup` function in the `templates/` directory can prove they are safe to use.Source: Red Hat security advisory for CVE-2020-11013 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2020-11013 in your dependencies?
Find it across Go, including transitive dependencies.