# GHSA-wc5v-r48v-g4vh: Cilium host policy bypass in endpoint-routes mode with dual-stack

> Attackers can bypass host firewall policies for IPv6 traffic from Cilium-managed pods to the host network in specific dual-stack configurations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jul 2022

## What is GHSA-wc5v-r48v-g4vh?

GHSA-wc5v-r48v-g4vh is a vulnerability in github.com/cilium/cilium, published on 15 Jul 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

### Impact

This vulnerability allows bypassing host policies for IPv6 traffic coming from a Cilium-managed pod and destined to the host-network namespace (e.g., to a host-network pod). Host policy enforcement on IPv4 or for traffic coming from outside the node is not affected.

Cilium is only affected by this vulnerability if IPv4, IPv6, endpoint routes, and the host firewall are enabled. Note that endpoint routes are typically only enabled in GKE, EKS, AKS, and OpenShift; in those environments, IPv6 is typically disabled. Host firewall is disabled by default.

### Patches

The bug is fixed in versions v1.10.13 and v1.11.7 of Cilium.

### Workarounds

For affected users who can't upgrade, one potential workaround is to ensure all pods have network policies that prevent sending arbitrary traffic to the local node.

### References

Commit fixing the vulnerability: https://github.com/cilium/cilium/commit/c758da7e9d19cd19b96dc90424c0b5ec7409cd0a.

### For more information

If you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack).

As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: [security@cilium.io](mailto:security@cilium.io)—first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.

## Which versions are affected by GHSA-wc5v-r48v-g4vh?

4 open source packages ship an affected version, including github.com/cilium/cilium.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/cilium/cilium` | Go | All versions | 1.10.13 |
| `github.com/cilium/cilium` | Go | All versions | 1.10.13 |
| `github.com/cilium/cilium` | Go | From 1.11.0 | 1.11.7 |
| `github.com/cilium/cilium` | Go | From 1.11.0 | 1.11.7 |

## How do I fix GHSA-wc5v-r48v-g4vh?

Upgrade github.com/cilium/cilium to a fixed version for your release line: 1.10.13 or 1.11.7.

## Is GHSA-wc5v-r48v-g4vh being exploited?

There is no known exploitation of GHSA-wc5v-r48v-g4vh in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-wc5v-r48v-g4vh and fix it if it is affected.

What it is: GHSA-wc5v-r48v-g4vh is a vulnerability in github.com/cilium/cilium, published on 15 Jul 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-wc5v-r48v-g4vh in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/cilium/cilium (Go): affected all versions; fixed in 1.10.13
- github.com/cilium/cilium (Go): affected all versions; fixed in 1.10.13
- github.com/cilium/cilium (Go): affected from 1.11.0; fixed in 1.11.7
- github.com/cilium/cilium (Go): affected from 1.11.0; fixed in 1.11.7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-wc5v-r48v-g4vh/ (Markdown: https://insights.sbomify.com/GHSA-wc5v-r48v-g4vh/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-wc5v-r48v-g4vh

---
From sbomify Insights: https://insights.sbomify.com/GHSA-wc5v-r48v-g4vh/
Summaries are generated and may contain mistakes; the official description above is the record.