Auth bypass in Cilium

CVE-2023-27594

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.11.15, 1.12.8, and 1.13.1, under specific conditions, Cilium may misattribute the source IP address of traffic to a cluster, identifying external traffic as coming from the host on which Cilium is running. As a consequence, network policies for that cluster might be bypassed, depending on the specific network policies enabled. This issue only manifests when Cilium is routing IPv6 traffic and NodePorts are used to route traffic to pods. IPv6 and endpoint routes are both disabled by default. The problem has been fixed and is available on versions 1.11.15, 1.12.8, and 1.13.1. As a workaround, disable IPv6 routing.

EPSS: 0.006 (42.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

  • Cilium — versions < 1.11.15, >= 1.12.0, < 1.12.8, >= 1.13.0, < 1.13.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-27594?
CVE-2023-27594 is a medium-severity vulnerability in Cilium, classified under Improper Authorization. CVSS score: 4.2/10. Published 2023-03-17.
How severe is CVE-2023-27594?
Medium severity. CVSS v3 base score is 4.2 out of 10.