If using extended-form privilege documents it is impossible to run the copyDB and clone commands if auth is enabled. See the discussion in SERVER-7864 as to why this is hard to fix.
copydb command doesn't support role based access control
Using copyDatabase to copy from an unauthenticated instance to an authenticated instance fails
Make copydb command work with auth on mongos
not authorized to execute repairDatabase for user with role clusterAdmin
Make copyDB, cloneDB, etc. work with auth when using old-style users