The flaw lies in the validation of the Host field of TCPSocket or HTTPGet handlers in PodProbeMarker objects. The admission webhook does not constrain this field, and because kruise‑daemon operates with hostNetwork=true, the probes execute in the node’s network namespace. This turns the node into a proxy that can reach internal or external services specified by the attacker, resulting in server‑side request forgery (SSRF). The consequence is a breach of confidentiality and network isolation, potentially exposing private networks or other cluster nodes. The weakness is a classic insecure input validation issue (CWE‑918).

Affected systems include deployments of OpenKruise Kruise version 1.7.4 and earlier, and versions up to 1.8.2. Versions 1.8.3 and 1.7.5 are patched and no longer vulnerable. If a user employs a different branch or fork it is recommended to review the same code path that is impacted in the released patches.

The EPSS score is below 1%, indicating a very low current exploitation probability, and the vulnerability is not listed in CISA’s KEV catalog. Nonetheless, because the flaw allows arbitrary network requests from the node, the potential impact is significant if an attacker gains PodProbeMarker creation rights. The control plane’s admission webhook is a central point of attack, and exploitation requires the ability to create or modify PodProbeMarker objects. The attack vector is inferred to be from within the cluster, leveraging permissions to create PodProbeMarker resources.