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.
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 - 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.
References
Impact
This issue only impacts users who:
toEndpointsANDIn 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:
It should be rewritten to:
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.
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 - 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.
References