GHSA-f4p5-x4vc-mh4v Improper use of metav1.Duration allows for Denial of Service

• Go github.com/fluxcd/flux2: >= 0.1.0, < 0.35.0 → fixed in 0.35.0 • Go github.com/fluxcd/source-controller: >= 0.0.1-alpha-1, < 0.30.0 → fixed in 0.30.0 • Go github.com/fluxcd/kustomize-controller: >= 0.0.1-alpha-1, < 0.29.0 → fixed in 0.29.0 • Go github.com/fluxcd/helm-controller: >= 0.0.1-alpha-1, < 0.24.0 → fixed in 0.24.0 • Go github.com/fluxcd/notification-controller: >= 0.0.1-alpha-1, < 0.27.0 → fixed in 0.27.0 • Go github.com/fluxcd/image-automation-controller: >= 0.1.0, < 0.26.0 → fixed in 0.26.0 • Go github.com/fluxcd/image-reflector-controller: >= 0.1.0, < 0.22.0 → fixed in 0.22.0 • Go github.com/fluxcd/helm-controller/api: < 0.26.0 → fixed in 0.26.0 • Go github.com/fluxcd/image-automation-controller/api: < 0.26.1 → fixed in 0.26.1 • Go github.com/fluxcd/image-reflector-controller/api: < 0.22.1 → fixed in 0.22.1 • Go github.com/fluxcd/kustomize-controller/api: < 0.30.0 → fixed in 0.30.0 • Go github.com/fluxcd/notification-controller/api: < 0.28.0 → fixed in 0.28.0 • Go github.com/fluxcd/source-controller/api: < 0.30.0 → fixed in 0.30.0

Flux controllers within the affected versions range are vulnerable to a denial of service attack. Users that have permissions to change Flux’s objects, either through a Flux source or directly within a cluster, can provide invalid data to fields `.spec.interval` or `.spec.timeout` (and structured variations of these fields), causing the entire object type to stop being processed. The issue has two root causes: a) the Kubernetes type `metav1.Duration` not being fully compatible with the Go type `time.Duration` as explained on upstream report; b) lack of validation within Flux to restrict allowed values. Workarounds Admission controllers can be employed to restrict the values that can be used for fields `.spec.interval` and `.spec.timeout`, however upgrading to the latest versions is still the recommended mitigation. Credits This issue was reported by Alexander Block (@codablock) through the Flux security mailing list (as recommended). For more information If you have any questions or comments about this advisory: • Open an issue in any of the affected repositories. • Contact us at the CNCF Flux channel. References • https://github.com/kubernetes/apimachinery/issues/131