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CiliumApplication

CVE-2023-39347

CRITICAL · 9.0 CVSS v3.1 Published 2023-09-27
Fix available
A fix is available. Upgrade to 1.12.14 / 1.13.7 or later.
See remediation →
92/100
Remediation priority · Urgent
Public exploit Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CiliumApplication
Affected:< 1.12.14>= 1.13.0, < 1.13.7>= 1.14.0, < 1.14.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.12.14 / 1.13.7 / 1.14.2 or later
Fixed in 1.12.141.13.71.14.2
Recommended fix High confidence

Cilium 1.14.2 (or 1.13.7 or 1.12.14 depending on your branch)

  1. Identify the currently running Cilium version using `cilium version` or `kubectl get nodes -o jsonpath='{.items[*].status.nodeInfo.kubeletVersion}'`
  2. Plan the upgrade based on your current version: if on 1.12.x upgrade to 1.12.14, if on 1.13.x upgrade to 1.13.7, if on 1.14.0-1.14.1 upgrade to 1.14.2
  3. Review the Cilium upgrade guide at https://docs.cilium.io/en/stable/operations/upgrade/ for your environment
  4. For Helm-based installations, upgrade with: `helm upgrade cilium cilium/cilium --version <fixed-version> --namespace kube-system`
  5. For CLI-based upgrades, follow the standard upgrade procedure for your deployment type
  6. After upgrade, verify the Cilium version with `cilium version`
  7. Test that network policies are being correctly applied by creating a test policy and verifying enforcement
  8. Alternatively, as a mitigation without upgrading, deploy an admission webhook (such as Kyverno or OPA/Gatekeeper) to block updates to labels `k8s:io.kubernetes.pod.namespace` and `io.cilium.k8s.policy.*`
Caveat Standard Cilium minor version upgrade considerations apply; review release notes for any behavioral changes between your current and target version

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,300. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

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Peer-ranked notes from engineers who’ve handled CVE-2023-39347 in production — separate from our analysis above.

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