GHSA-2h44-x2wx-49f4

Potential HTTP policy bypass when using header rules in Cilium

### Impact This issue only impacts users who: - Have a HTTP policy that applies to multiple `toEndpoints` AND - Have an allow-all rule in place that affects only one of those endpoints In such cases, a wildcard rule will be appended to the set of HTTP rules, which could cause bypass of HTTP policies. ### Patches This issue has been patched in Cilium 1.11.16, 1.12.9, and 1.13.2. ### Workarounds Rewrite HTTP rules for each endpoint separately. For example, if the initial rule looks like: ``` egress: - toEndpoints: - matchLabels: k8s:kind: echo - matchLabels: k8s:kind: example toPorts: - ports: - port: "8080" protocol: TCP rules: http: - method: "GET" ``` It should be rewritten to: ``` egress: - toEndpoints: - matchLabels: k8s:kind: echo toPorts: - ports: - port: "8080" protocol: TCP rules: http: - method: "GET" - toEndpoints: - matchLabels: k8s:kind: example toPorts: - ports: - port: "8080" protocol: TCP rules: http: - method: "GET" ``` ### Acknowledgements The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @jrajahalme for investigating and fixing the issue. ### 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.