Information
The table function SYSPROC.AUTH_LIST_AUTHORITIES_FOR_AUTHID returns the instance and database authorities for the specified authorization ID. In a non-restrictive database this table function has EXECUTE granted to public. It is recommended that public should not be able to execute this routine.
Rationale:
A malicious user may use this function to conduct information gathering regarding users that have high level authorities.
Solution
Perform the following to revoke access from PUBLIC.
Connect to the Db2 database.
db2 => connect to <dbname>
Run the following command:
db2 => revoke EXECUTE on function
SYSPROC.AUTH_LIST_AUTHORITIES_FOR_AUTHID
from public RESTRICT