How to access a SYSTEM owned custom table through EM - Configuration Extension

Hi,

I am writing a custom configuration extension and using the following SQL, table "mysession_log" is custom table owned by SYSTEM. After associating the targets getting the error "Failed to execute query. Cause-Failed to prepare sql query. ORA-01031: insufficient privileges (DBD ERROR: error possibly near <*> indicator at char 28 in 'select username from system.<*>mysession_log')"

select username from SYSTEM.mysession_log

I am not sure what is the issue here, I logged into the DB using SYSMAN account and can able to query the table. So is it really a permission issue or else we can't access custom SYSTEM owned tables using EM?