RCE in Fluxcd Flux2
CVE-2022-24817
Flux2 is an open and extensible continuous delivery solution for Kubernetes. Flux2 versions between 0.1.0 and 0.29.0, helm-controller 0.1.0 to v0.19.0, and kustomize-controller 0.1.0 to v0.23.0 are vulnerable to Code Injection via malicious Kubeconfig. In multi-tenancy deployments this can also lead to privilege escalation if the controller's service account has elevated permissions. Workarounds include disabling functionality via Validating Admission webhooks by restricting users from setting the `spec.kubeConfig` field in Flux `Kustomization` and `HelmRelease` objects. Additional mitigations include applying restrictive AppArmor and SELinux profiles on the controller’s pod to limit what binaries can be executed. This vulnerability is fixed in kustomize-controller v0.23.0 and helm-controller v0.19.0, both included in flux2 v0.29.0
Vulnerability class: RCE (Remote Code Execution)
EPSS: 0.011 (61.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Fluxcd Flux2 — versions flux2 < v0.29.0 >= v0.1.0, helm-controller < v0.23.0 >= v0.1.0, kustomize-controller < v0.19.0 >= v0.2.0
- Fluxcd Helm-controller
- Fluxcd Kustomize-controller
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2022-24817?
- CVE-2022-24817 is a critical-severity vulnerability in Fluxcd Flux2, classified under Code Injection. CVSS score: 9.9/10. Published 2022-05-06.
- How severe is CVE-2022-24817?
- Critical severity. CVSS v3 base score is 9.9 out of 10.