Cilium packets from terminating endpoints may not be encrypted in Wireguard-enabled clusters

Vulnerability Description

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.15.0 to 1.15.15, 1.16.0 to 1.16.8, and 1.17.0 to 1.17.2, are vulnerable when using Wireguard transparent encryption in a Cilium cluster, packets that originate from a terminating endpoint can leave the source node without encryption due to a race condition in how traffic is processed by Cilium. This issue has been patched in versions 1.15.16, 1.16.9, and 1.17.3. There are no workarounds available for this issue.

References

• https://github.com/cilium/cilium/security/advisories/GHSA-5vxx-c285-pcq4
• https://github.com/cilium/cilium/pull/38592