GMS-2023-799: `cilium-cli` disables etcd authorization for clustermesh clusters

Impact

cilium-cli, when used to configure cluster mesh functionality, can remove the enforcement of user permissions on the etcd store used to mirror local cluster information to remote clusters.

Due to an incorrect mount point specification, the settings specified by the initContainer that configures etcd users and their permissions are overwritten when using cilium-cli to configure a cluster mesh. An attacker who has already gained access to a valid key and certificate for an etcd cluster compromised in this manner could then modify state in that etcd cluster.

Patches

This issue is patched in cilium-cli 0.13.2

All previous versions of cilium-cli are affected. Users who have set up cluster meshes using the Cilium Helm chart are not affected.

Workarounds

Use Cilium’s Helm charts to create your cluster instead.

Acknowledgements

The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to Marco Iorio for investigating and fixing the issue.

For more information

If you have any questions or comments about this advisory, please reach out on Slack.

As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: security@cilium.io - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.