Kubernetes Config Connector Misconfiguration Can Grant Namespace Users GCP Organization Ownership

Summary

A user able to create IAMPolicyMember resources in a KCC-managed namespace may exploit KCC’s broadly privileged service account to grant themselves Google Cloud organization-level access, without cloud credentials.

Key points

KCC uses its own Google Cloud service account to process resource requests, so Google Cloud IAM sees KCC—not the Kubernetes user who initiated them.
A user with permission to create IAMPolicyMember resources in a watched namespace may use KCC’s authority to grant themselves roles/owner at the organization level.
The article calls this ConfigConfusion, a confused deputy problem discovered by security researcher Justin O’Leary.
Google says KCC is working as designed; the risk depends on administrators granting KCC broad cloud permissions while allowing users to submit powerful IAM resources.
Mitigations include using namespaced mode and separately scoped service accounts, narrowing KCC’s IAM roles, restricting IAM resource creation, and monitoring organization-level changes.

Article Details

Attack Vectors: A user with permission to create IAMPolicyMember resources in a KCC-managed Kubernetes namespace submits a resource that grants their service account a Google Cloud role the KCC service account can assign.
KCC processes the resource using its own service account. If that account has organization-level permissions, the user can escalate to organization ownership without Google Cloud credentials of their own.
Defensive Notes: Use KCC namespaced mode with a separately scoped Google service account for each namespace.
Review KCC's IAM roles at the project, folder, and organization levels; remove broad roles such as roles/owner and roles/resourcemanager.organizationAdmin unless strictly required.
Restrict permission to create IAMPolicyMember, IAMPolicy, and IAMPartialPolicy resources to approved platform or infrastructure teams.
Monitor folder- and organization-level IAM changes made by KCC, particularly changes outside the approved GitOps workflow.