Cilium
CVE-2023-41333
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication required for critical functions
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 8.1 (HIGH). Attack characteristics: adjacent network attack vector, low complexity, high privileges required, no user interaction not required. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to access critical functionality without authentication. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAI
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Rated high severity (CVSS 8.1), this vulnerability is low attack complexity. This Missing Authentication for Critical Function vulnerability could allow attackers to access critical functionality without authentication.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Require authentication for all sensitive operations, implement defense in depth.
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 as Missing Authentication for Critical Function (CWE-306), which allows attackers to access critical functionality without authentication. Cilium is a networking, observability, and security solution with an eBPF-based dataplane. An attacker with the ability to create or modify CiliumNetworkPolicy objects in a particular namespace is able to affect traffic on an entire Cilium cluster, potentially bypassing policy enforcement in other namespaces. By using a crafted endpointSelector that uses the DoesNotExist operator on the reserved:init label, the attacker can create policies that bypass namespace restrictions and affect the entire Cilium cluster. This includes potentially allowing or denying all traffic. This attack requires API server access, as described in the Kubernetes API Server Attacker section of the Cilium Threat Model. This issue has been resolved in Cilium versions 1.14.2, 1.13.7, and 1.12.14. As a workaround an admission webhook can be used to prevent the use of endpointSelectors that use the DoesNotExist operator on the reserved:init label in CiliumNetworkPolicies. Affected products include: Cilium.
Know when Cilium gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:A/AC:L/PR:H/UI:N/S:C/C:N/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 create or modify CiliumNetworkPolicy objects in a particular namespace is able to affect traffic on an entire Cilium cluster, potentially bypassing policy enforcement in other namespaces. By using a crafted endpointSelector that uses the DoesNotExist operator on the reserved:init label, the attacker can create policies that bypass namespace restrictions and affect the entire Cilium cluster. This includes potentially allowing or denying all traffic. This attack requires API server access, as described in the Kubernetes API Server Attacker section of the Cilium Threat Model. This issue has been resolved in Cilium versions 1.14.2, 1.13.7, and 1.12.14. As a workaround an admission webhook can be used to prevent the use of endpointSelectors that use the DoesNotExist operator on the reserved:init label in CiliumNetworkPolicies.
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
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 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