PostgreSQL must protect its audit features from unauthorized access.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-73039	PGS9-00-010700	SV-87691r1_rule		Medium

Description
Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data. Depending upon the log format and application, system and application log tools may provide the only means to manipulate and manage application and system log data. It is, therefore, imperative that access to audit tools be controlled and protected from unauthorized access. Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, OS-provided audit tools, vendor-provided audit tools, and open source audit tools needed to successfully view and manipulate audit information system activity and records. If an attacker were to gain access to audit tools, he could analyze audit logs for system weaknesses or weaknesses in the auditing itself. An attacker could also manipulate logs to hide evidence of malicious activity.

Description

Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data. Depending upon the log format and application, system and application log tools may provide the only means to manipulate and manage application and system log data. It is, therefore, imperative that access to audit tools be controlled and protected from unauthorized access. Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, OS-provided audit tools, vendor-provided audit tools, and open source audit tools needed to successfully view and manipulate audit information system activity and records. If an attacker were to gain access to audit tools, he could analyze audit logs for system weaknesses or weaknesses in the auditing itself. An attacker could also manipulate logs to hide evidence of malicious activity.

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

Details

Check Text ( C-73171r5_chk )
Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA. Only the database owner and superuser can alter configuration of PostgreSQL. Make sure the pg_log directory are owned by postgres user and group: $ sudo su - postgres $ ls -la ${PGDATA?}/pg_log If pg_log is not owned by the database owner, this is a finding. Make sure the data directory are owned by postgres user and group. $ sudo su - postgres $ ls -la ${PGDATA?} If PGDATA is not owned by the database owner, this is a finding. Make sure pgaudit installation is owned by root: $ sudo su - postgres $ ls -la /usr/pgsql-9.5/share/contrib/pgaudit If pgaudit installation is not owned by root, this is a finding. Next, as the database administrator (shown here as "postgres"), run the following SQL to list all roles and their privileges: $ sudo su - postgres $ psql -x -c "\du" If any role has "superuser" that should not, this is a finding.

Check Text ( C-73171r5_chk )

Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA. Only the database owner and superuser can alter configuration of PostgreSQL.

Make sure the pg_log directory are owned by postgres user and group:

$ sudo su - postgres
$ ls -la ${PGDATA?}/pg_log

If pg_log is not owned by the database owner, this is a finding.

Make sure the data directory are owned by postgres user and group.

$ sudo su - postgres
$ ls -la ${PGDATA?}

If PGDATA is not owned by the database owner, this is a finding.

Make sure pgaudit installation is owned by root:

$ sudo su - postgres
$ ls -la /usr/pgsql-9.5/share/contrib/pgaudit

If pgaudit installation is not owned by root, this is a finding.

Next, as the database administrator (shown here as "postgres"), run the following SQL to list all roles and their privileges:

$ sudo su - postgres
$ psql -x -c "\du"

If any role has "superuser" that should not, this is a finding.

Fix Text (F-79485r1_fix)
Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA. If pg_log or data directory are not owned by postgres user and group, configure them as follows: $ sudo chown -R postgres:postgres ${PGDATA?} If the pgaudit installation is not owned by root user and group, configure it as follows: $ sudo chown -R root:root /usr/pgsql-9.5/share/contrib/pgaudit. To remove superuser from a role, as the database administrator (shown here as "postgres"), run the following SQL: $ sudo su - postgres $ psql -c "ALTER ROLE WITH NOSUPERUSER"

Fix Text (F-79485r1_fix)

Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA.

If pg_log or data directory are not owned by postgres user and group, configure them as follows:

$ sudo chown -R postgres:postgres ${PGDATA?}

If the pgaudit installation is not owned by root user and group, configure it as follows:

$ sudo chown -R root:root /usr/pgsql-9.5/share/contrib/pgaudit.

To remove superuser from a role, as the database administrator (shown here as "postgres"), run the following SQL:

$ sudo su - postgres
$ psql -c "ALTER ROLE WITH NOSUPERUSER"