API Server DoS (crash?) if many large resources (~1MB each) are concurrently/repeatedly sent to an external Validating WebHook endpoint

Summary: I was trying to explore a way to stealthily send lots of data outside a private GKE cluster by way of misusing the Validating Webhook mechanism. The idea would be that a cluster-admin could install a webhook and then initiate resources (like a secret or configmap) that contains the data to …

{
  "major": "1",
  "minor": "17+",
  "gitVersion": "v1.17.14-gke.1600",
  "gitCommit": "7c407f5cc8632f9af5a2657f220963aa7f1c46e7",
  "gitTreeState": "clean",
  "buildDate": "2020-12-07T09:22:27Z",
  "goVersion": "go1.13.15b4",
  "compiler": "gc",
  "platform": "linux/amd64"
}