CVE-2024-42487: Cilium's Gateway API route matching order contradicts specification
Impact
Gateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched (HTTPRouteRule, GRPCRouteRule).
If users create Gateway API resources that use both request headers and request methods in order to route to different destinations, then traffic may be delivered to the incorrect backend. If the backend does not have Network Policy restricting acceptable traffic to receive, then requests may access information that you did not intend for them to access.
Patches
This issue was fixed in https://github.com/cilium/cilium/pull/34109.
This issue affects: - Cilium v1.15 between v1.15.0 and v1.15.7 inclusive - Cilium v1.16.0
This issue is fixed in: - Cilium v1.15.8 - Cilium v1.16.1
Workarounds
There is no workaround for this issue.
Acknowledgements
The Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for remediating this issue.
Further 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 security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Other sources
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In the 1.15 branch prior to 1.15.8 and the 1.16 branch prior to 1.16.1, Gateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched. This could result in unexpected behaviour with security This issue is fixed in Cilium v1.15.8 and v1.16.1. There is no workaround for this issue.
— MITRE
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2024-42487?
CVE-2024-42487 is categorized as a moderate severity vulnerability due to its impact on request routing in the Gateway API.
How do I fix CVE-2024-42487?
To remediate CVE-2024-42487, update Cilium to version 1.15.8 or 1.16.1.
What software is affected by CVE-2024-42487?
CVE-2024-42487 affects Cilium versions between 1.15.0 and 1.15.8, as well as version 1.16.0.
What are the consequences of CVE-2024-42487?
CVE-2024-42487 can lead to unexpected routing behavior due to incorrect matching precedence of request methods and headers.
Is there a known exploit for CVE-2024-42487?
As of now, there are no publicly known exploits specifically targeting CVE-2024-42487.