KubeCon + CloudNativeCon China 2025

Maximizing security in multi-tenant clusters while maintaining cost-effectiveness is crucial for enterprise OPS. Most enterprise clusters deploy multiple daemonsets, which are attractive targets for attackers seeking to escape and move laterally, ultimately taking over the entire cluster.

The SIG community has introduced several advanced security features recently, such as CRD Field Selectors, Field and Label Selector Authorization, validating admission policy (VAP), and Structured Authorization Config. These allow users to define more flexible authorization configurations, addressing filtering and authorization needs for CRDs, kubelet, and other resources in multi-tenant environments.

We will share the lessons learned from the node escape incidents and demonstrate how to implement these new features and show how to use the Common Expression Language (CEL) to configure customized policies in Authorization Webhook and VAP, resulting more node-specific restrictions within clusters.