Dgraph: Pre-Auth Database Overwrite + SSRF + File Read via restoreTenant Missing Authorization
The restoreTenant admin mutation is missing from the authorization middleware config (admin.go:499-522), making it completely unauthenticated. Unlike the similar restore mutation which requires Guardian-of-Galaxy authentication, restoreTenant executes with zero middleware. This mutation accepts attacker-controlled backup source URLs (including file:// for local filesystem access), S3/MinIO credentials, encryption key file paths, and Vault credential file paths. An unauthenticated attacker can overwrite the entire database, read server-side files, and perform SSRF.