From SQL*Plus (NOTE: The owner list below is a short list of all possible default Oracle accounts and roles):
select grantee||': '||granted_role from dba_role_privs
where grantee not in
('ANONYMOUS','AURORA$JIS$UTILITY$',
'AURORA$ORB$UNAUTHENTICATED','CTXSYS','DBSNMP','DIP',
'DMSYS','DVF','DVSYS','EXFSYS','LBACSYS','MDDATA','MDSYS',
'MGMT_VIEW','ODM','ODM_MTR','OLAPSYS','ORDPLUGINS','ORDSYS',
'OSE$HTTP$ADMIN','OUTLN','PERFSTAT','REPADMIN','RMAN',
'SI_INFORMTN_SCHEMA','SYS','SYSMAN','SYSTEM','TRACESVR',
'TSMSYS','WK_TEST','WKPROXY','WKSYS','WKUSER','WMSYS','XDB')
and grantee not in
('DBA', 'OLAP_USER', 'IP', 'ORASSO_PUBLIC',
'PORTAL_PUBLIC', 'DATAPUMP_EXP_FULL_DATABASE',
'DATAPUMP_IMP_FULL_DATABASE', 'EXP_FULL_DATABASE',
'IMP_FULL_DATABASE', 'OLAP_DBA', 'EXECUTE_CATALOG_ROLE',
'SELECT_CATALOG_ROLE', 'JAVASYSPRIV')
and grantee not in
(select grantee from dba_role_privs where granted_role = 'DBA')
and grantee not in (select distinct owner from dba_objects)
and granted_role in
('AQ_ADMINISTRATOR_ROLE','AQ_USER_ROLE',
'CTXAPP',
'DELETE_CATALOG_ROLE','EJBCLIENT','EXECUTE_CATALOG_ROLE',
'EXP_FULL_DATABASE','GATHER_SYSTEM_STATISTICS',
'GLOBAL_AQ_USER_ROLE','HS_ADMIN_ROLE',
'IMP_FULL_DATABASE','JAVADEBUGPRIV','JAVAIDPRIV',
'JAVASYSPRIV','JAVAUSERPRIV','JAVA_ADMIN','JAVA_DEPLOY',
'LOGSTDBY_ADMINISTRATOR','OEM_MONITOR','OLAP_DBA',
'RECOVERY_CATALOG_OWNER',
'SALES_HISTORY_ROLE','SELECT_CATALOG_ROLE','WKUSER',
'WM_ADMIN_ROLE','XDBADMIN')
and granted_role not in ('CONNECT', 'RESOURCE', 'AUTHENTICATEDUSER')
order by grantee;
If any records are returned, confirm the grantee and role are documented in the System Security Plan and authorized by the IAO.
If not documented and approved, this is a Finding.