Ensure that access to SYSIBM.SYSSCHEMAAUTH is restricted

MediumLevel 1Manual reviewdb2-zos

Description

The SYSIBM.SYSSCHEMAAUTH table contains a list of all users who have one or more privileges or access to a particular schema. PUBLIC should be restricted from accessing this table. PUBLIC should not have access to this list of users. Preventing PUBLIC to access sensitive information reduces the risk to your organization's data.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

For Db2 internal security users: Issue the following SQL statement to check if PUBLIC has access: SELECT GRANTEE FROM SYSIBM.SYSTABAUTH WHERE TCREATOR = 'SYSIBM' AND TTNAME = 'SYSSCHEMAAUTH' AND GRANTEE = 'PUBLIC'; Output that contains zero rows is considered a successful finding. Otherwise, PUBLIC has SELECT privilege and the remediation steps should be followed. For external security users: Issue the RACF RLIST command to list the profile that controls access to the SYSIBM.SYSSCHEMAAUTH table in the MDSNTB class. Examine the universal access (UACC) and ... (full steps: CIS section 2.2.23)

How it is fixed

Fix method: Guidance or infrastructure patch

For Db2 internal security users: Issue the following SQL statement to revoke access from PUBLIC: REVOKE ALL ON SYSIBM.SYSSCHEMAAUTH FROM PUBLIC; For external security users: Issue the RACF RALTER command to update the profile and change the UACC setting to NONE. Issue the RACF PERMIT command to remove the ID(*) and specify users or groups.

Properties

Operating systems: Any
Tags: db2-zospermissions
Reference: CIS IBM Db2 13 for z/OS Benchmark v1.0.0 - 2.2.23 Ensure that access to SYSIBM.SYSSCHEMAAUTH is restricted