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CiliumApplication

CVE-2023-27594

HIGH · 7.3 CVSS v3.1 Published 2023-03-17
Fix available
A fix is available. Upgrade to 1.11.15 / 1.12.8 or later.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges 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. 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.

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 · high confidence

In Cilium prior to versions 1.11.15, 1.12.8, and 1.13.1, when IPv6 routing and NodePorts are both enabled, external IPv6 traffic destined to pods via NodePorts may have its source IP incorrectly attributed to the host rather than the actual external origin. This causes network policies that rely on source IP filtering to be bypassed since the traffic appears to originate from an internal host IP.

MitigationUpgrade Cilium to version 1.11.15, 1.12.8, or 1.13.1 or higher. Alternatively, if upgrading is not immediately feasible, disable IPv6 routing as a workaround.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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:< 1.11.15>= 1.12.0, < 1.12.8>= 1.13.0, < 1.13.1

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Cilium version
    Run 'cilium version' or 'kubectl get deployment -n kube-system cilium-operator -o jsonpath={.spec.template.spec.containers[0].image}' to retrieve the Cilium version running in the cluster
    Affected if The version is less than 1.11.15, or between 1.12.0 and 1.12.7 inclusive, or between 1.13.0 and 1.13.0 inclusive
  2. Verify IPv6 routing is enabled
    Check the Cilium ConfigMap in the kube-system namespace: 'kubectl get configmap cilium-config -n kube-system -o jsonpath={.data.enable-ipv6-routing}' or inspect the daemonSet: 'kubectl get ds cilium -n kube-system -o jsonpath={.spec.template.spec.containers[0].env[?(@.name=="ENABLE_IPV6_ROUTING")].value}'
    Affected if The output is 'true' or '1', indicating IPv6 routing is enabled
  3. Confirm NodePort service type is in use
    List services with type NodePort: 'kubectl get svc --all-namespaces -o jsonpath={.items[?(@.type=="NodePort")].metadata.name}' or check Cilium configuration for NodePort enablement: 'kubectl get configmap cilium-config -n kube-system -o jsonpath={.data.enable-node-port}'
    Affected if Any service exposes NodePort OR the node-port configuration is enabled in Cilium
  4. Check for IPv6 NodePort exposure
    Identify services exposing NodePorts with IPv6: 'kubectl get svc --all-namespaces -o jsonpath={range .items[*]}{.metadata.name}{"\t"}{.spec.ports[*].nodePort}{"\t"}{.spec.type}{"\n"}{end}' and verify the node is reachable via IPv6
    Affected if NodePort services exist and the cluster nodes have IPv6 addresses assigned

The environment is affected if the installed Cilium version is vulnerable AND IPv6 routing is enabled AND NodePorts are exposed, allowing external IPv6 traffic to bypass source IP-based network policies.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 1.11.15 / 1.12.8 / 1.13.1 or later
Fixed in 1.11.151.12.81.13.1
Interim mitigation

Upgrade Cilium to version 1.11.15, 1.12.8, or 1.13.1 or higher. Alternatively, if upgrading is not immediately feasible, disable IPv6 routing as a workaround.

Recommended fix High confidence

1.11.15 (for 1.11.x users), 1.12.8 (for 1.12.x users), or 1.13.1 (for 1.13.x users)

  1. Upgrade to Cilium version 1.11.15, 1.12.8, or 1.13.1 (or later) depending on your current branch
  2. As an alternative workaround if upgrade is not immediately feasible, disable IPv6 routing in the Cilium configuration

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

Fix this in Cilium Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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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

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-27594 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data