Information
The SYSIBM.SYSROUTINEAUTH table contains a list of all users that have EXECUTE privilege on a routine (function, method, or procedure). It is recommended that the PUBLIC role be restricted from accessing this table.
Rationale:
PUBLIC should not have access to see all the users because this could be used as a point of exploit.
Solution
Perform the following to revoke access from PUBLIC.
Connect to the Db2 database.
db2 => connect to <dbname>
Run the following command:
db2 => REVOKE SELECT ON SYSIBM.SYSROUTINEAUTH FROM PUBLIC