GHSA-xg58-75qf-9r67
MEDIUMCilium's Layer 7 policy enforcement may not occur in policies with wildcarded port ranges
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/cilium/ciliumReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
For users with the following configuration:
- An allow policy that selects a Layer 3 identity and a port range AND
- A Layer 7 allow policy that selects a specific port within the first policy's range
then Layer 7 enforcement would not occur for the traffic selected by the Layer 7 policy.
This issue only affects users who use Cilium's port range functionality, which was introduced in Cilium v1.16.
For reference, an example of a pair of policies that would trigger this issue is:
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "layer-3-and-4"
spec:
endpointSelector:
matchLabels:
app: service
ingress:
- fromCIDR:
- 192.168.60.0/24
toPorts:
- ports:
- port: "80"
endPort: 444
protocol: TCP
and
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
name: "layer-4-and-7"
spec:
endpointSelector:
matchLabels:
app: service
ingress:
toPorts:
- ports:
- port: "80"
protocol: TCP
rules:
http:
- method: "GET"
path: "/public"
In the above example, requests would be permitted to all HTTP paths on matching endpoints, rather than just GET requests to the /public path as intended by the layer-4-and-7 policy. In patched versions of Cilium, the layer-4-and-7 rule would take precedence over the layer-3-and-4 rule.
Patches
This issue is patched in https://github.com/cilium/cilium/pull/35150.
This issue affects Cilium v1.16 between v1.16.0 and v1.16.3 inclusive.
This issue is patched in Cilium v1.16.4.
Workarounds
Users with network policies that match the pattern described above can work around the issue by rewriting any policies that use port ranges to individually specify the ports permitted for traffic.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @jrajahalme for resolving this issue.
For more information
If you have any questions or comments about this advisory, please reach out on Slack.
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [email protected]. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cilium/cilium | ≥ 1.16.0&&< 1.16.4 | 1.16.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/cilium/cilium to 1.16.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xg58-75qf-9r67 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xg58-75qf-9r67 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xg58-75qf-9r67. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xg58-75qf-9r67 in your dependencies?
O3 detects GHSA-xg58-75qf-9r67 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.