KubeSphere: SSRF via Unvalidated Cluster CRD Connection Endpoint in Cluster Reconciliation
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.5epss 0.2%
exploitation probability
0.2%top 89% of all CVEs
observed exploitation
nono source reports it
KubeSphere's cluster-controller reconciliation (pkg/utils/clusterclient/clusterclient.go, addCluster) processes every Cluster custom resource's connection configuration and immediately calls Discovery().ServerVersion() against the CRD-specified Kubernetes API endpoint, which is parsed only for URL syntax (url.Parse) with no allow/deny-list for loopback, RFC1918 private ranges, link-local, or cloud-metadata addresses (e.g. 169.254.169.254). A user able to create or update a Cluster CRD can force the controller-manager and apiserver pods to issue outbound requests to arbitrary internal or metadata endpoints.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Affected products
kubesphere · KubeSphere