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Fencer Vulns
medium 6.9

CVE-2023-41333 json

Bypass of namespace restrictions in CiliumNetworkPolicy

published 2023-09-26 3 y ago modified 2026-09-10 1 mo ago also 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 , BIT-hubble-ui-backend-2023-41333 , EUVD-2023-2423 , GHSA-4xp2-w642-7mcx , GO-2023-2080

cvss
6.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/cilium/cilium 1.12.14, 1.13.7, 1.14.2
  • bitnami cilium 1.12.14, 1.13.7, 1.14.2
  • bitnami cilium-operator 1.12.14, 1.13.7, 1.14.2
  • bitnami cilium-proxy 1.12.14, 1.13.7, 1.14.2
  • bitnami hubble 1.12.14, 1.13.7, 1.14.2
  • bitnami hubble-relay 1.12.14, 1.13.7, 1.14.2
  • bitnami hubble-ui 1.12.14, 1.13.7, 1.14.2
  • bitnami hubble-ui-backend 1.12.14, 1.13.7, 1.14.2
  • cilium cilium 1.12.14, 1.13.7, 1.14.2

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.9 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:H
GitHub 3.1 6.9 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:H
NVD 3.1 8.1 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H
OSV 3.1 8.1 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H

Affected packages

ecosystem package affected fixed in
go github.com/cilium/cilium
>=1.14.0, <1.14.2
>=1.13.0, <1.13.7
<1.12.14
1.14.2
1.13.7
1.12.14
bitnami cilium
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami cilium-operator
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami cilium-proxy
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami hubble
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami hubble-relay
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami hubble-ui
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2
bitnami hubble-ui-backend
<1.12.14
>=1.13.0, <1.13.7
>=1.14.0, <1.14.2
1.12.14
1.13.7
1.14.2

Affected products

  • cilium cilium

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.