CVE-2023-41333 Bypass of namespace restrictions in CiliumNetworkPolicy

What is CVE-2023-41333?

CVE-2023-41333 is a medium-severity missing authorization vulnerability in cilium, published on 26 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-306

Which versions are affected by CVE-2023-41333?

14 open source packages ship an affected version, including github.com/cilium/cilium, cilium and cilium-operator. It affects 1 product.

Products include Cilium Cilium.

How do I fix CVE-2023-41333?

Upgrade github.com/cilium/cilium to a fixed version for your release line: 1.12.14, 1.13.7 or 1.14.2.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2023-41333 being exploited?

There is no known exploitation of CVE-2023-41333 in the wild and no public exploit code.

Other vulnerabilities in cilium

• CVE-2026-49445 Cilium: Sensitive information disclosure and cluster disruption via local Envoy admin socket access Critical 9.2
• CVE-2022-29178 Incorrect Default Permissions in Cilium High 8.8
• CVE-2024-28860 Insecure IPsec transport encryption in Cilium High 8.0
• CVE-2026-41520 Cillium exposes sensitive information included in the cilium-bugtool debug archive High 7.9
• CVE-2024-37307 Cilium leaks sensitive information in cilium-bugtool High 7.9

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-cilium-2023-41333, BIT-cilium-operator-2023-41333, BIT-cilium-proxy-2023-41333, BIT-hubble-2023-41333, BIT-hubble-relay-2023-41333, BIT-hubble-ui-2023-41333 and 3 more.