Karmada PULL Mode Cluster Privilege Escalation

Karmada is a Kubernetes management system that allows users to run cloud-native applications across multiple Kubernetes clusters and clouds. Prior to version 1.12.0, the PULL mode clusters registered with the karmadactl register command have excessive privileges to access control plane resources. By abusing these permissions, an attacker able to authenticate as the karmada-agent to a karmada cluster would be able to obtain administrative privileges over the entire federation system including all registered member clusters. Since Karmada v1.12.0, command karmadactl register restricts the access permissions of pull mode member clusters to control plane resources. This way, an attacker able to authenticate as the karmada-agent cannot control other member clusters in Karmada. As a workaround, one may restrict the access permissions of pull mode member clusters to control plane resources according to Karmada Component Permissions Docs.