PostgreSQL must generate time stamps, for audit records and application data, with a minimum granularity of one second.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-72985	PGS9-00-007700	SV-87637r2_rule		Medium

Description
Without sufficient granularity of time stamps, it is not possible to adequately determine the chronological order of records. Time stamps generated by PostgreSQL must include date and time. Granularity of time measurements refers to the precision available in time stamp values. Granularity coarser than one second is not sufficient for audit trail purposes. Time stamp values are typically presented with three or more decimal places of seconds; however, the actual granularity may be coarser than the apparent precision. For example, PostgreSQL will always return at least millisecond timestamps but it can be truncated using EXTRACT functions: SELECT EXTRACT(MINUTE FROM TIMESTAMP '2001-02-16 20:38:40');.

Description

Without sufficient granularity of time stamps, it is not possible to adequately determine the chronological order of records. Time stamps generated by PostgreSQL must include date and time. Granularity of time measurements refers to the precision available in time stamp values. Granularity coarser than one second is not sufficient for audit trail purposes. Time stamp values are typically presented with three or more decimal places of seconds; however, the actual granularity may be coarser than the apparent precision. For example, PostgreSQL will always return at least millisecond timestamps but it can be truncated using EXTRACT functions: SELECT EXTRACT(MINUTE FROM TIMESTAMP '2001-02-16 20:38:40');.

STIG	Date
PostgreSQL 9.x Security Technical Implementation Guide	2017-12-27

Details

Check Text ( C-73115r1_chk )
Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA. First, as the database administrator (shown here as "postgres"), verify the current log_line_prefix setting by running the following SQL: $ sudo su - postgres $ psql -c "SHOW log_line_prefix" If log_line_prefix does not contain %m, this is a finding. Next check the logs to verify time stamps are being logged: $ sudo su - postgres $ cat ${PGDATA?}/pg_log/ < 2016-02-23 12:53:33.947 EDT postgres postgres 570bd68d.3912 >LOG: connection authorized: user=postgres database=postgres < 2016-02-23 12:53:41.576 EDT postgres postgres 570bd68d.3912 >LOG: AUDIT: SESSION,1,1,DDL,CREATE TABLE,,,CREATE TABLE test_srg(id INT);, < 2016-02-23 12:53:44.372 EDT postgres postgres 570bd68d.3912 >LOG: disconnection: session time: 0:00:10.426 user=postgres database=postgres host=[local] If time stamps are not being logged, this is a finding.

Check Text ( C-73115r1_chk )

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

First, as the database administrator (shown here as "postgres"), verify the current log_line_prefix setting by running the following SQL:

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

If log_line_prefix does not contain %m, this is a finding.

Next check the logs to verify time stamps are being logged:

$ sudo su - postgres
$ cat ${PGDATA?}/pg_log/
< 2016-02-23 12:53:33.947 EDT postgres postgres 570bd68d.3912 >LOG: connection authorized: user=postgres database=postgres
< 2016-02-23 12:53:41.576 EDT postgres postgres 570bd68d.3912 >LOG: AUDIT: SESSION,1,1,DDL,CREATE TABLE,,,CREATE TABLE test_srg(id INT);,
< 2016-02-23 12:53:44.372 EDT postgres postgres 570bd68d.3912 >LOG: disconnection: session time: 0:00:10.426 user=postgres database=postgres host=[local]

If time stamps are not being logged, this is a finding.

Fix Text (F-79431r2_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. PostgreSQL will not log anything if logging is not enabled. To ensure that logging is enabled, review supplementary content APPENDIX-C for instructions on enabling logging. If logging is enabled the following configurations must be made to log events with time stamps: First, as the database administrator (shown here as "postgres"), edit postgresql.conf: $ sudo su - postgres $ vi ${PGDATA?}/postgresql.conf Add %m to log_line_prefix to enable time stamps with milliseconds: log_line_prefix = '< %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

Fix Text (F-79431r2_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.

PostgreSQL will not log anything if logging is not enabled. To ensure that logging is enabled, review supplementary content APPENDIX-C for instructions on enabling logging.

If logging is enabled the following configurations must be made to log events with time stamps:

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

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

Add %m to log_line_prefix to enable time stamps with milliseconds:

log_line_prefix = '< %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