CVE-2023-27593

Summary

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.11.15, 1.12.8, and 1.13.1, an attacker with access to a Cilium agent pod can write to /opt/cni/bin due to a hostPath mount of that directory in the agent pod. By replacing the CNI binary with their own malicious binary and waiting for the creation of a new pod on the node, the attacker can gain access to the underlying node.

The issue has been fixed and the fix is available on versions 1.11.15, 1.12.8, and 1.13.1. Some workarounds are available. Kubernetes RBAC should be used to deny users and service accounts exec access to Cilium agent pods. In cases where a user requires exec access to Cilium agent pods, but should not have access to the underlying node, no workaround is possible.

Affected Software

VendorProductVersion RangeStatus
ciliumcilium< 1.11.15affected
ciliumcilium>= 1.12.0, < 1.12.8affected
ciliumcilium>= 1.13.0, < 1.13.1affected

Weaknesses

  • CWE-276: CWE-276: Incorrect Default Permissions

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References