{"id":"CVE-2023-30851","aliases":["BIT-cilium-2023-30851","BIT-cilium-operator-2023-30851","BIT-cilium-proxy-2023-30851","BIT-hubble-2023-30851","BIT-hubble-relay-2023-30851","BIT-hubble-ui-2023-30851","BIT-hubble-ui-backend-2023-30851","GHSA-2h44-x2wx-49f4","GO-2023-1785"],"url":"https://o3.security/vulnerability/CVE-2023-30851","summary":"Potential HTTP policy bypass when using header rules in Cilium","details":"### Impact\n\nThis issue only impacts users who:\n\n- Have a HTTP policy that applies to multiple `toEndpoints` AND\n- Have an allow-all rule in place that affects only one of those endpoints\n\nIn such cases, a wildcard rule will be appended to the set of HTTP rules, which could cause bypass of HTTP policies.\n\n### Patches\n\nThis issue has been patched in Cilium 1.11.16, 1.12.9, and 1.13.2.\n\n### Workarounds\n\nRewrite HTTP rules for each endpoint separately. For example, if the initial rule looks like:\n\n```\n  egress:\n    - toEndpoints:\n        - matchLabels:\n            k8s:kind: echo\n        - matchLabels:\n            k8s:kind: example\n      toPorts:\n        - ports:\n            - port: \"8080\"\n              protocol: TCP\n          rules:\n            http:\n              - method: \"GET\"\n```\n\nIt should be rewritten to:\n \n```\n  egress:\n    - toEndpoints:\n        - matchLabels:\n            k8s:kind: echo\n      toPorts:\n        - ports:\n            - port: \"8080\"\n              protocol: TCP\n          rules:\n            http:\n              - method: \"GET\"\n    - toEndpoints:\n        - matchLabels:\n            k8s:kind: example\n      toPorts:\n        - ports:\n            - port: \"8080\"\n              protocol: TCP\n          rules:\n            http:\n              - method: \"GET\"\n```     \n\n### Acknowledgements\n\nThe Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @jrajahalme for investigating and fixing the issue.\n\n### For more information\n\nIf you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack).\n\nAs 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.\n","published":"2023-05-25T17:47:51.095Z","modified":"2026-08-12T03:51:14.434414930Z","cvss":{"score":2.6,"severity":"LOW","vector":"CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:C/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.11.16"},{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.12.9"},{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.13.2"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.11.16"},{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.12.9"},{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.13.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/30xxx/CVE-2023-30851.json"},{"type":"ADVISORY","url":"https://github.com/cilium/cilium/security/advisories/GHSA-2h44-x2wx-49f4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-30851"},{"type":"PACKAGE","url":"https://github.com/cilium/cilium"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:14.434414930Z"}}