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GHSA-24qp-4xx8-3jvj BIT-cilium-2025-30162 BIT-cilium-operator-2025-30162 BIT-hubble-relay-2025-30162 CVE-2025-30162 GO-2025-3560

Cilium East-west traffic not subject to egress policy enforcement for requests via Gateway API load balancers

Medium Go
Severity
3.2 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
0.22%
Chance of exploitation in the next 30 days. Higher than 13.06% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-863 Incorrect Authorization
Fix
1.16.8
Upgrade github.com/cilium/cilium to this version or later

Description

Impact

For Cilium users who:

  • Use Gateway API for Ingress for some services AND
  • Use LB-IPAM or BGP for LB Service implementation AND
  • Use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces

Egress traffic from workloads covered by such network policies to LoadBalancers configured by Gateway resources will incorrectly be allowed.

LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue.

Patches

This issue was fixed by https://github.com/cilium/proxy/pull/1172.

This issue affects:

  • Cilium v1.15 between v1.15.0 and v1.15.14 inclusive
  • Cilium v1.16 between v1.16.0 and v1.16.7 inclusive
  • Cilium v1.17 between v1.17.0 and v1.17.1 inclusive

This issue is fixed in:

  • Cilium v1.15.15
  • Cilium v1.16.8
  • Cilium v1.17.2

Workarounds

A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade. An outline of such a policy is provided below:

apiVersion: "cilium.io/v2"
kind: CiliumClusterwideNetworkPolicy
metadata:
  name: "workaround"
spec:
  endpointSelector:
    matchExpressions:
    - key: reserved:ingress
      operator: Exists
  ingress:
  - fromEntities:
    - world
  • The policy opens up connectivity from all locations outside the cluster into the Cilium Ingress Gateway.
  • The policy establishes a default deny for all other traffic towards the Cilium Ingress Gateway, including all in-cluster sources.
  • It is possible to tailor the policy to more narrowly allow inbound traffic while creating a default deny posture for traffic between namespaces. Users should edit the policy to bring it in line with the security requirements particular to their environments.

Acknowledgements

The Cilium community has worked together with members of the Isovalent team to prepare these mitigations. Special thanks to @jrajahalme for the fix.

For more information

If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Affected versions

Go

PackageVulnerableFixed in
github.com/cilium/cilium
>= 1.16.0, < 1.16.8
1.16.8
github.com/cilium/cilium
>= 1.17.0, < 1.17.2
1.17.2
github.com/cilium/cilium
>= 1.15.0, < 1.15.15
1.15.15
github.com/cilium/cilium
>= 1.15.0, < 1.15.15
>= 1.16.0, < 1.16.8
>= 1.17.0, < 1.17.2
1.15.15
1.16.8
1.17.2

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/cilium/cilium Go → 1.16.8

go
go get github.com/cilium/cilium@v1.16.8 && go mod tidy

Severity breakdown

CVSS 3.1 3.2

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N

Attack vector
Local
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None

Weakness

CWE-863: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How to prevent it
  • Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
  • Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
  • System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-fm8w-2m5w-9j7r
Cilium may unexpectedly allow ingress traffic from the local namespace when a Kubernetes NetworkPolicy is configured with an ipBlock match
Medium Also affects github.com/cilium/cilium
GHSA-w7c2-w76w-5hmj
Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
High Also affects github.com/cilium/cilium
GHSA-q6h5-q3q6-f87x
CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
Medium Also affects github.com/cilium/cilium
GHSA-3fcv-jvfp-m4q9
Cilium vulnerable to sensitive information disclosure and cluster disruption via local Envoy admin socket access
High Also affects github.com/cilium/cilium
GHSA-gj49-89wh-h4gj
Cillium exposes sensitive information included in the cilium-bugtool debug archive
Medium Also affects github.com/cilium/cilium
GHSA-hxv8-4j4r-cqgv
Cilium L7 proxy may bypass Kubernetes NetworkPolicy for same-node traffic
Medium Also affects github.com/cilium/cilium
GHSA-5r23-prx4-mqg3
Cilium may not enforce host firewall policies when Native Routing, WireGuard and Node Encryption are enabled
Medium Also affects github.com/cilium/cilium
GHSA-38pp-6gcp-rqvm
Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Medium Also affects github.com/cilium/cilium
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