Cilium
CVE-2023-39347
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A08:2025 - Software or Data Integrity Failures
ASVS 5.0
V15 - Secure Coding and Architecture Data authenticity verification
|
| Impact | CVSS score of 9.0 (CRITICAL). Attack characteristics: adjacent network attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | Successful exploitation could compromise the critical-severity affected system. |
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Alert meAnalysisAI
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated critical severity (CVSS 9.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in go
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-345. 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. Affected products include: Cilium.
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Severity by source
AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)NVD
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated critical severity (CVSS
Cross-namespace authorization bypass in Cilium's Gateway API implementation (versions prior to 1.17.17, 1.18.11, and 1.1
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 8.7
Cilium is open source software for providing and securing network connectivity and loadbalancing between application wor
Cilium is open source software for providing and securing network connectivity and loadbalancing between application wor
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 8.1
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated low severity (CVSS 3.5)
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 7.3
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 7.2
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 7.2
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated medium severity (CVSS 6
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated medium severity (CVSS 6
Exploit-DB