PostgreSQL must generate audit records when unsuccessful attempts to execute privileged activities or other system-level access occur.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-72969	PGS9-00-006500	SV-87621r1_rule		Medium

Description
Without tracking privileged activity, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. System documentation should include a definition of the functionality considered privileged. A privileged function in this context is any operation that modifies the structure of the database, its built-in logic, or its security settings. This would include all Data Definition Language (DDL) statements and all security-related statements. In an SQL environment, it encompasses, but is not necessarily limited to: CREATE ALTER DROP GRANT REVOKE Note: That it is particularly important to audit, and tightly control, any action that weakens the implementation of this requirement itself, since the objective is to have a complete audit trail of all administrative activity. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

Description

Without tracking privileged activity, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. System documentation should include a definition of the functionality considered privileged. A privileged function in this context is any operation that modifies the structure of the database, its built-in logic, or its security settings. This would include all Data Definition Language (DDL) statements and all security-related statements. In an SQL environment, it encompasses, but is not necessarily limited to: CREATE ALTER DROP GRANT REVOKE Note: That it is particularly important to audit, and tightly control, any action that weakens the implementation of this requirement itself, since the objective is to have a complete audit trail of all administrative activity. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

STIG	Date
PostgreSQL 9.x Security Technical Implementation Guide	2017-01-20

Details

Check Text ( C-73099r2_chk )
As the database administrator (shown here as "postgres"), create the role bob by running the following SQL: $ sudo su - postgres $ psql -c "CREATE ROLE bob" Next, change the current role to bob and attempt to execute privileged activity: $ psql -c "CREATE ROLE stig_test SUPERUSER" $ psql -c "CREATE ROLE stig_test CREATEDB" $ psql -c "CREATE ROLE stig_test CREATEROLE" $ psql -c "CREATE ROLE stig_test CREATEUSER" Now, as the database administrator (shown here as "postgres"), verify that an audit event was produced (use the latest log): $ sudo su - postgres $ cat ${PGDATA?}/pg_log/ < 2016-02-23 20:16:32.396 EST postgres 56cfa74f.79eb postgres: >ERROR: must be superuser to create superusers < 2016-02-23 20:16:32.396 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test SUPERUSER; < 2016-02-23 20:16:48.725 EST postgres 56cfa74f.79eb postgres: >ERROR: permission denied to create role < 2016-02-23 20:16:48.725 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEDB; < 2016-02-23 20:16:54.365 EST postgres 56cfa74f.79eb postgres: >ERROR: permission denied to create role < 2016-02-23 20:16:54.365 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEROLE; < 2016-02-23 20:17:05.949 EST postgres 56cfa74f.79eb postgres: >ERROR: must be superuser to create superusers < 2016-02-23 20:17:05.949 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEUSER; If audit records are not produced, this is a finding.

Check Text ( C-73099r2_chk )

As the database administrator (shown here as "postgres"), create the role bob by running the following SQL:

$ sudo su - postgres
$ psql -c "CREATE ROLE bob"

Next, change the current role to bob and attempt to execute privileged activity:

$ psql -c "CREATE ROLE stig_test SUPERUSER"
$ psql -c "CREATE ROLE stig_test CREATEDB"
$ psql -c "CREATE ROLE stig_test CREATEROLE"
$ psql -c "CREATE ROLE stig_test CREATEUSER"

Now, as the database administrator (shown here as "postgres"), verify that an audit event was produced (use the latest log):

$ sudo su - postgres
$ cat ${PGDATA?}/pg_log/
< 2016-02-23 20:16:32.396 EST postgres 56cfa74f.79eb postgres: >ERROR: must be superuser to create superusers
< 2016-02-23 20:16:32.396 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test SUPERUSER;
< 2016-02-23 20:16:48.725 EST postgres 56cfa74f.79eb postgres: >ERROR: permission denied to create role
< 2016-02-23 20:16:48.725 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEDB;
< 2016-02-23 20:16:54.365 EST postgres 56cfa74f.79eb postgres: >ERROR: permission denied to create role
< 2016-02-23 20:16:54.365 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEROLE;
< 2016-02-23 20:17:05.949 EST postgres 56cfa74f.79eb postgres: >ERROR: must be superuser to create superusers
< 2016-02-23 20:17:05.949 EST postgres 56cfa74f.79eb postgres: >STATEMENT: CREATE ROLE stig_test CREATEUSER;

If audit records are not produced, this is a finding.

Fix Text (F-79415r1_fix)
Configure PostgreSQL to produce audit records when unsuccessful attempts to execute privileged SQL. All denials are logged by default if logging is enabled. To ensure that logging is enabled, review supplementary content APPENDIX-C for instructions on enabling logging.