Unencrypted traffic between nodes when using IPsec and L7 policies

Impact

In Cilium clusters with IPsec enabled and traffic matching Layer 7 policies:

• Traffic that should be IPsec-encrypted between a node’s Envoy proxy and pods on other nodes is sent unencrypted
• Traffic that should be IPsec-encrypted between a node’s DNS proxy and pods on other nodes is sent unencrypted

Note: For clusters running in native routing mode, IPsec encryption is not applied to connections which are selected by a L7 Egress Network Policy or a DNS Policy. This is a known limitation of Cilium’s IPsec encryption which will continue to apply after upgrading to the latest Cilium versions described below.

Patches

This issue affects:

• Cilium v1.15 before v1.15.2
• Cilium v1.14 before v1.14.8
• Cilium v1.13 before v1.13.13
• Cilium v1.4 to v1.12 inclusive

This issue has been resolved in:

• Cilium v1.15.2
• Cilium v1.14.8
• Cilium v1.13.13

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 @jschwinger233, @julianwiedmann, @giorio94, and @jrajahalme for their work in triaging and resolving this issue.

For more information

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

If you think you have found a vulnerability in Cilium, we strongly encourage you to report it to our private security mailing list at [email protected]. This is a private mailing list that only members of the Cilium internal security team are subscribed to, and your report will be treated as top priority.