PGS9-00-000400 - The audit information produced by PostgreSQL must be protected from unauthorized modification - log directory


If audit data were to become compromised, then competent forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve.

To ensure the veracity of audit data the information system and/or the application must protect audit information from unauthorized modification.

This requirement can be achieved through multiple methods that will depend upon system architecture and design. Some commonly employed methods include ensuring log files enjoy the proper file system permissions and limiting log data locations.

Applications providing a user interface to audit data will leverage user permissions and roles identifying the user accessing the data and the corresponding rights that the user enjoys in order to make access decisions regarding the modification of audit data.

Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity.

Modification of database audit data could mask the theft of, or the unauthorized modification of, sensitive data stored in the database.


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

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

#### stderr Logging

With stderr logging enabled, as the database owner (shown here as 'postgres'), set the following parameter in postgresql.conf:

$ vi ${PGDATA?}/postgresql.conf
log_file_mode = 0600

To change the owner and permissions of the log files, run the following:

$ chown postgres:postgres ${PGDATA?}/
$ chmod 0700 ${PGDATA?}/
$ chmod 600 ${PGDATA?}//*.log

#### syslog Logging

If PostgreSQL is configured to use syslog for logging, the log files must be configured to be owned by root with 0600 permissions.

$ chown root:root /
$ chmod 0700
$ chmod 0600 /*.log

Supportive Information

The following resource is also helpful.

This security hardening control applies to the following category of controls within NIST 800-53: Audit and Accountability.This control applies to the following type of system Unix.