Title

PostgreSQL must be able to generate audit records when privileges/permissions are retrieved. (Cat II impact)

Discussion

Under some circumstances, it may be useful to monitor who/what is reading privilege/permission/role information. Therefore, it must be possible to configure auditing to do this. PostgreSQLs typically make such information available through views or functions. This requirement addresses explicit requests for privilege/permission/role membership information. It does not refer to the implicit retrieval of privileges/permissions/role memberships that PostgreSQL continually performs to determine if any and every action on the database is permitted.

Check Content

Note: The following instructions use the PGLOG environment variable. See supplementary content APPENDIX-I for instructions on configuring PGLOG. First, as the database administrator (shown here as "postgres"), check if pgaudit is enabled by running the following SQL: $ sudo su - postgres $ psql -c "SHOW shared_preload_libraries" If pgaudit is not found in the results, this is a finding. Next, as the database administrator (shown here as "postgres"), list all role memberships for the database: $ sudo su - postgres $ psql -c "\du" Next, verify the query was logged: $ sudo su - postgres $ cat ${PGLOG?}/<latest_log> This should, as an example, return (among other rows): 2016-01-28 19:43:12.126 UTC postgres postgres: >LOG: AUDIT: SESSION,1,1,READ,SELECT,,,"SELECT r.rolname, r.rolsuper, r.rolinherit, r.rolcreaterole, r.rolcreatedb, r.rolcanlogin, r.rolconnlimit, r.rolvaliduntil, ARRAY(SELECT b.rolname FROM pg_catalog.pg_auth_members m JOIN pg_catalog.pg_roles b ON (m.roleid = b.oid) WHERE m.member = r.oid) as memberof , r.rolreplication , r.rolbypassrls FROM pg_catalog.pg_roles r ORDER BY 1;",<none> If audit records are not produced, this is a finding.

Fix Text

Note: The following instructions use the PGDATA and PGVER environment variables. See supplementary content APPENDIX-F for instructions on configuring PGDATA and APPENDIX-H for PGVER. Using pgaudit PostgreSQL can be configured to audit these requests. See supplementary content APPENDIX-B for documentation on installing pgaudit. With pgaudit installed the following configurations can be made: $ sudo su - postgres $ vi ${PGDATA?}/postgresql.conf Add the following parameters (or edit existing parameters): pgaudit.log_catalog = 'on' pgaudit.log = 'read' Now, as the system administrator, reload the server with the new configuration: $ sudo systemctl reload postgresql-${PGVER?}

Additional Identifiers

Rule ID: SV-233562r879561_rule

Vulnerability ID: V-233562

Group Title: SRG-APP-000091-DB-000066

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.