OpenKruise PodProbeMarker is Vulnerable to SSRF via Unrestricted Host Field

Kruise provides automated management of large-scale applications on Kubernetes. Prior to versions 1.8.3 and 1.7.5, PodProbeMarker allows defining custom probes with TCPSocket or HTTPGet handlers. The webhook validation does not restrict the Host field in these probe configurations. Since kruise-daemon runs with hostNetwork=true, it executes probes from the node network namespace. An attacker with PodProbeMarker creation permission can specify arbitrary Host values to trigger SSRF from the node, perform port scanning, and receive response feedback through NodePodProbe status messages. Versions 1.8.3 and 1.7.5 patch the issue.