Impact
CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended.
Patches
This issue has been patched in:
Cilium v1.18.4 Cilium v1.17.10 Cilium v1.16.17
This issue affects:
- Cilium v1.18 between v1.18.0 and v1.18.3 inclusive - Cilium v1.17 between v1.17.0 and v1.17.9 inclusive - Cilium v1.16.16 and below
Workarounds
There is no workaround to this issue.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @SeanEmac for reporting this issue and to @fristonio for the patch.
For more information
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Impact
For Cilium users who: - Use Gateway API for Ingress for some services AND - Use LB-IPAM or BGP for LB Service implementation AND - Use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces
Egress traffic from workloads covered by such network policies to LoadBalancers configured by Gateway resources will incorrectly be allowed.
LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue.
Patches
This issue was fixed by https://github.com/cilium/proxy/pull/1172.
This issue affects:
- Cilium v1.15 between v1.15.0 and v1.15.14 inclusive - Cilium v1.16 between v1.16.0 and v1.16.7 inclusive - Cilium v1.17 between v1.17.0 and v1.17.1 inclusive
This issue is fixed in:
- Cilium v1.15.15 - Cilium v1.16.8 - Cilium v1.17.2
Workarounds
A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade. An outline of such a policy is provided below:
apiVersion: "cilium.io/v2" kind: CiliumClusterwideNetworkPolicy metadata: name: "workaround" spec: endpointSelector: matchExpressions: - key: reserved:ingress operator: Exists ingress: - fromEntities: - world
- The policy opens up connectivity from all locations outside the cluster into the Cilium Ingress Gateway. - The policy establishes a default deny for all other traffic towards the Cilium Ingress Gateway, including all in-cluster sources. - It is possible to tailor the policy to more narrowly allow inbound traffic while creating a default deny posture for traffic between namespaces. Users should edit the policy to bring it in line with the security requirements particular to their environments.
Acknowledgements
The Cilium community has worked together with members of the Isovalent team to prepare these mitigations. Special thanks to @jrajahalme for the fix.
For more information
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Impact
Node based network policies (fromNodes and toNodes) will incorrectly permit traffic to/from non-node endpoints that share the labels specified in fromNodes and toNodes sections of network policies. Node based network policy is disabled by default in Cilium.
Patches
This issue was fixed by https://github.com/cilium/cilium/pull/36657.
This issue affects:
- Cilium v1.16 between v1.16.0 and v1.16.7 inclusive - Cilium v1.17 between v1.17.0 and v1.17.1 inclusive
This issue is fixed in:
- Cilium v1.16.8 - Cilium v1.17.2
Workarounds
Users can work around this issue by ensuring that the labels used in fromNodes and toNodes fields are used exclusively by nodes and not by other endpoints.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @oblazek for reporting and fixing this issue.
For more information
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority. Please also address any comments or questions on this advisory to the same mailing list.