CVE-2023-39347 Information

Description

Cilium is a networking observability and security solution with an eBPF-based dataplane. An attacker with the ability to update pod labels can cause Cilium to apply incorrect network policies. This issue arises due to the fact that on pod update Cilium incorrectly uses user-provided pod labels to select the policies which apply to the workload in question. This can affect Cilium network policies that use the namespace service account or cluster constructs to restrict traffic Cilium clusterwide network policies that use Cilium namespace labels to select the Pod and Kubernetes network policies. Non-existent construct names can be provided which bypass all network policies applicable to the construct. For example providing a pod with a non-existent namespace as the value of the io.kubernetes.pod.namespace label results in none of the namespaced CiliumNetworkPolicies applying to the pod in question. This attack requires the attacker to have Kubernetes API Server access as described in the Cilium Threat Model. This issue has been resolved in: Cilium versions 1.14.2 1.13.7 and 1.12.14. Users are advised to upgrade. As a workaround an admission webhook can be used to prevent pod label updates to the k8s:io.kubernetes.pod.namespace and io.cilium.k8s.policy. keys.

CVSS Vector

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Reference

https://github.com/cilium/cilium/security/advisories/GHSA-gj2r-phwg-6rww https://docs.cilium.io/en/latest/security/threat-model/#kubernetes-api-server-attacker

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.0