Information
A tablespace is where the data is physically stored. It is recommended that tablespace usage be restricted to authorized users.
Rationale:
Grant the USE of tablespace privilege to only authorized users. Restrict the privilege from PUBLIC, where applicable, as a malicious user can cause a denial of service at the tablespace level by overloading it with corrupted data.
Solution
Perform the following to revoke access from PUBLIC.
Connect to the Db2 database.
db2 => connect to <dbname>
Run the following command:
db2 => REVOKE USE OF TABLESPACE [$tablespace_name\] FROM PUBLIC