PostgreSQL must protect against a user falsely repudiating having performed organization-defined actions.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-73019	PGS9-00-009700	SV-87671r2_rule		Medium

Description
Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables, and configuring PostgreSQL' audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to PostgreSQL, even where the application connects to PostgreSQL with a standard, shared account.

Description

Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables, and configuring PostgreSQL' audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to PostgreSQL, even where the application connects to PostgreSQL with a standard, shared account.

STIG	Date
PostgreSQL 9.x Security Technical Implementation Guide	2020-03-23

Details

Check Text ( C-73151r2_chk )
First, as the database administrator, review the current log_line_prefix settings by running the following SQL: $ sudo su - postgres $ psql -c "SHOW log_line_prefix" If log_line_prefix does not contain at least '< %m %a %u %d %r %p %m >', this is a finding. Next, review the current shared_preload_libraries settings by running the following SQL: $ psql -c "SHOW shared_preload_libraries" If shared_preload_libraries does not contain "pgaudit", this is a finding.

Check Text ( C-73151r2_chk )

First, as the database administrator, review the current log_line_prefix settings by running the following SQL:

$ sudo su - postgres
$ psql -c "SHOW log_line_prefix"

If log_line_prefix does not contain at least '< %m %a %u %d %r %p %m >', this is a finding.

Next, review the current shared_preload_libraries settings by running the following SQL:

$ psql -c "SHOW shared_preload_libraries"

If shared_preload_libraries does not contain "pgaudit", this is a finding.

Fix Text (F-79465r2_fix)
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. Configure the database to supply additional auditing information to protect against a user falsely repudiating having performed organization-defined actions. Using pgaudit PostgreSQL can be configured to audit these requests. See supplementary content APPENDIX-B for documentation on installing pgaudit. To ensure that logging is enabled, review supplementary content APPENDIX-C for instructions on enabling logging. Modify the configuration of audit logs to include details identifying the individual user: First, as the database administrator (shown here as "postgres"), edit postgresql.conf: $ sudo su - postgres $ vi ${PGDATA?}/postgresql.conf Extra parameters can be added to the setting log_line_prefix to identify the user: log_line_prefix = '< %m %a %u %d %r %p %m >' Now, as the system administrator, reload the server with the new configuration: # SYSTEMD SERVER ONLY $ sudo systemctl reload postgresql-${PGVER?} # INITD SERVER ONLY $ sudo service postgresql-${PGVER?} reload Use accounts assigned to individual users. Where the application connects to PostgreSQL using a standard, shared account, ensure that it also captures the individual user identification and passes it to PostgreSQL.

Fix Text (F-79465r2_fix)

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.

Configure the database to supply additional auditing information to protect against a user falsely repudiating having performed organization-defined actions.

Using pgaudit PostgreSQL can be configured to audit these requests. See supplementary content APPENDIX-B for documentation on installing pgaudit.

To ensure that logging is enabled, review supplementary content APPENDIX-C for instructions on enabling logging.

Modify the configuration of audit logs to include details identifying the individual user:

First, as the database administrator (shown here as "postgres"), edit postgresql.conf:

$ sudo su - postgres
$ vi ${PGDATA?}/postgresql.conf

Extra parameters can be added to the setting log_line_prefix to identify the user:

log_line_prefix = '< %m %a %u %d %r %p %m >'

Now, as the system administrator, reload the server with the new configuration:

# SYSTEMD SERVER ONLY
$ sudo systemctl reload postgresql-${PGVER?}

# INITD SERVER ONLY
$ sudo service postgresql-${PGVER?} reload

Use accounts assigned to individual users. Where the application connects to PostgreSQL using a standard, shared account, ensure that it also captures the individual user identification and passes it to PostgreSQL.