Cilium vulnerable to information leakage via incorrect ReferenceGrant update logic in Gateway API

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In versions on the 1.15.x branch prior to 1.15.8 and the 1.16.x branch prior to 1.16.1, ReferenceGrant changes are not correctly propagated in Cilium's GatewayAPI controller, which could lead to Gateway resources being able to access secrets for longer than intended, or to Routes having the ability to forward traffic to backends in other namespaces for longer than intended. This issue has been patched in Cilium v1.15.8 and v1.16.1. As a workaround, any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In versions on the 1.15.x branch prior to 1.15.8 and the 1.16.x branch prior to 1.16.1, ReferenceGrant changes are not correctly propagated in Cilium's GatewayAPI controller, which could lead to Gateway resources being able to access secrets for longer than intended, or to Routes having the ability to forward traffic to backends in other namespaces for longer than intended. This issue has been patched in Cilium v1.15.8 and v1.16.1. As a workaround, any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In versions on the 1.15.x branch prior to 1.15.8 and the 1.16.x branch prior to 1.16.1, ReferenceGrant changes are not correctly propagated in Cilium's GatewayAPI controller, which could lead to Gateway resources being able to access secrets for longer than intended, or to Routes having the ability to forward traffic to backends in other namespaces for longer than intended. This issue has been patched in Cilium v1.15.8 and v1.16.1. As a workaround, any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster.

### Impact Due to ReferenceGrant changes not being immediately propagated in Cilium's GatewayAPI controller, Gateway resources are able to access secrets in other namespaces after the associated ReferenceGrant has been revoked. This can lead to Gateways continuing to establish sessions using secrets that they should no longer have access to. ### Patches This issue was resolved in https://github.com/cilium/cilium/pull/34032. This issue affects: - Cilium v1.15 between v1.15.0 and v1.15.7 inclusive - Cilium v1.16.0 This issue has been patched in: - Cilium v1.15.8 - Cilium v1.16.1 ### Workarounds Any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster. ### Acknowledgements The Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for resolving this issue. ### For more information If you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack). If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [[email protected]](mailto:[email protected]). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Cilium leaks information via incorrect ReferenceGrant update logic in Gateway API in github.com/cilium/cilium