Cloudflare Pages Flaws Exposed Git Credentials and Enabled Container-to-Host Access

Researchers reported a chain of vulnerabilities in Cloudflare Pages build infrastructure that enabled command injection through user-controlled build settings, exposing sensitive pipeline variables including a GitHub private key for the Pages integration application and Cloudflare API credentials. The key reportedly carried read/write access to repositories for 18,290 users that had authorized the app. Subsequent findings included a world-writable binary, PATH hijacking, Azure DevOps variable injection, and passwordless sudo for the pipeline user; from a container, accessible Docker socket access allegedly allowed creation of a privileged container and recovery of Azure DevOps tokens used to enumerate Pages projects and build history.

After Cloudflare re-architected the environment around GKE and gVisor, researchers found that build containers could still reach Kubernetes host services. An unauthenticated kubelet API on TCP port 10255 exposed /pods data, including pod environment variables such as GIT_CREDS; scanning the 10.124.0.0/16 range identified multiple similarly exposed hosts, creating potential cross-tenant credential exposure. Cloudflare reportedly remediated the command-injection issue within two days and later implemented network isolation to prevent pod-to-host communication, an essential control where Kubernetes NetworkPolicy-capable networking is used to restrict L3/L4 ingress and egress paths.