CVE-2025-64715: Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Impact
CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended.
Patches
This issue has been patched in:
Cilium v1.18.4 Cilium v1.17.10 Cilium v1.16.17
This issue affects:
- Cilium v1.18 between v1.18.0 and v1.18.3 inclusive - Cilium v1.17 between v1.17.0 and v1.17.9 inclusive - Cilium v1.16.16 and below
Workarounds
There is no workaround to this issue.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @SeanEmac for reporting this issue and to @fristonio for the patch.
For more information
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. Prior to versions 1.16.17, 1.17.10, and 1.18.4, CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended. This issue has been patched in versions 1.16.17, 1.17.10, and 1.18.4. There are no workarounds for this issue.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
go/github.com/cilium/ciliumto a version that resolves this vulnerability.Fixed in 1.16.17 - Upgrade
Upgrade
go/Ciliumgithub.com/cilium/ciliumto a version that resolves this vulnerability.Fixed in 1.17.10 - Upgrade
Upgrade
go/github.com/cilium/ciliumto a version that resolves this vulnerability.Fixed in 1.18.4 - Upgrade
Upgrade
Ciliumto a version that resolves this vulnerability.Fixed in 1.16.17 - Upgrade
Upgrade
Ciliumto a version that resolves this vulnerability.Fixed in 1.17.10 - Upgrade
Upgrade
Ciliumto a version that resolves this vulnerability.Fixed in 1.18.4
Event History
Frequently Asked Questions
What is the severity of CVE-2025-64715?
The severity of CVE-2025-64715 has been assessed as medium due to potential unauthorized access through misconfigured AWS security groups.
How do I fix CVE-2025-64715?
To fix CVE-2025-64715, upgrade Cilium to versions 1.16.17, 1.17.10, or 1.18.4 or later.
What impacts does CVE-2025-64715 have on Cilium users?
CVE-2025-64715 can lead to improper network policy enforcement if referencing non-existent AWS security groups.
Are all versions of Cilium affected by CVE-2025-64715?
Yes, Cilium versions prior to 1.16.17, 1.17.10, and 1.18.4 are vulnerable to CVE-2025-64715.
What is the exposure risk associated with CVE-2025-64715?
The exposure risk associated with CVE-2025-64715 involves potential unauthorized network traffic due to misconfigured security group references.