Summary
Improper kubeconfig validation allows arbitrary code execution
Flux2 can reconcile the state of a remote cluster when provided with a kubeconfig with the correct access rights. Kubeconfig files can define commands to be executed to generate on-demand authentication tokens. A malicious user with write access to a Flux source or direct access to the target cluster, could craft a kubeconfig to execute arbitrary code inside the controller’s container.
In multi-tenancy deployments this can also lead to privilege escalation if the controller's service account has elevated permissions.
Workarounds
- The functionality can be disabled via Validating Admission webhooks (e.g. OPA Gatekeeper, Kyverno) by restricting users from being able to set the
spec.kubeConfigfield in FluxKustomizationandHelmReleaseobjects. - Applying restrictive AppArmor and SELinux profiles on the controller’s pod to limit what binaries can be executed.
Credits
The Flux engineering team found and patched this vulnerability.
For more information
If you have any questions or comments about this advisory please open an issue in the flux2 repository.
Impact
Within the affected versions range, one of the permissions set below would be required for the vulnerability to be exploited:
- Direct access to the cluster to create Flux
KustomizationorHelmReleaseobjects and Kubernetes Secrets. - Direct access to the cluster to modify existing Kubernetes secrets being used as
kubeconfigin existing FluxKustomizationorHelmReleaseobjects. - Direct access to the cluster to modify existing Flux
KustomizationorHelmReleaseobjects and access to create or modify existing Kubernetes secrets. - Access rights to make changes to a configured Flux Source (i.e. Git repository).
Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.
CVE-2022-24817 has a CVSS score of 9.9 (Critical). 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 (0.29.0, 0.23.0, 0.19.0); 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.
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This vulnerability was fixed in kustomize-controller v0.23.0 and helm-controller v0.19.0, both included in flux2 v0.29.0. Starting from the fixed versions, both controllers disable the use of command execution from kubeconfig files by default, users have to opt-in by adding the flag --insecure-kubeconfig-exec to the controller’s command arguments. Users are no longer allowed to refer to files in the controller’s filesystem in the kubeconfig files provided for the remote apply feature.
Frequently Asked Questions
- What is CVE-2022-24817? CVE-2022-24817 is a critical-severity code injection vulnerability in github.com/fluxcd/flux2 (go), affecting versions >= 0.1.0, < 0.29.0. It is fixed in 0.29.0, 0.23.0, 0.19.0. Untrusted input is evaluated as executable code within the application's runtime environment.
- How severe is CVE-2022-24817? CVE-2022-24817 has a CVSS score of 9.9 (Critical). 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 packages are affected by CVE-2022-24817?
github.com/fluxcd/flux2(go) (versions >= 0.1.0, < 0.29.0)github.com/fluxcd/kustomize-controller(go) (versions >= 0.1.0, < 0.23.0)github.com/fluxcd/helm-controller(go) (versions >= 0.2.0, < 0.19.0)
- Is there a fix for CVE-2022-24817? Yes. CVE-2022-24817 is fixed in 0.29.0, 0.23.0, 0.19.0. Upgrade to this version or later.
- Is CVE-2022-24817 exploitable, and should I be worried? Whether CVE-2022-24817 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-2022-24817 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-2022-24817?
- Upgrade
github.com/fluxcd/flux2to 0.29.0 or later - Upgrade
github.com/fluxcd/kustomize-controllerto 0.23.0 or later - Upgrade
github.com/fluxcd/helm-controllerto 0.19.0 or later
- Upgrade