CVE-2023-41333

What it is

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.

At a glance

Exploitability

Can be exploited from the same network segment with an admin-level account. High risk of service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-09-27 15:19 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 06:21 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 6.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-09-27 15:19 UTC

Last modified

2026-06-17 06:21 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-306 · Missing authentication

Record status

Modified

Affected

• Cilium < 1.12.14
• Cilium < 1.13.7
• Cilium < 1.14.2

Attack profile CVSS 3.1 · 6.9

Attack vector

Adjacent network

Complexity

Low

Privileges needed

High

User interaction

None

Scope

Changed

Confidentiality

Low

Integrity

None

Availability

High

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2023-41333.md and follow it. Check whether this project is affected by CVE-2023-41333. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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