Ensure 'log_line_prefix' is set correctly

MediumLevel 1Automatedpostgres

Description

The log_line_prefix setting specifies a printf-style string that is prefixed to each log line. If blank, no prefix is used. You should configure this as recommended by the pgBadger development team unless directed otherwise by your organization's logging policy. % characters begin "escape sequences" that are replaced with status information as outlined below. Requires the escapes %m %p %l %d %u %a %h (only %d %u %a %h when log_destination is syslog alone). Runs psql as ${PGUSER:-postgres} against ${PGDATABASE:-postgres}; set PGHOST/PGPORT and use ~/.pgpass (not PGPASSWORD, see 1.6/1.7) when peer authentication is not available.

How it is checked

Audit method: SQL query

sql_query

out=$(psql -X -U "${PGUSER:-postgres}" -d "${PGDATABASE:-postgres}" -tAc "SELECT CASE WHEN (SELECT (d = 'syslog' OR (strpos(s, '%m') > 0 AND strpos(s, '%p') > 0 AND strpos(s, '%l') > 0)) AND strpos(s, '%d') > 0 AND strpos(s, '%u') > 0 AND strpos(s, '%a') > 0 AND strpos(s, '%h') > 0 FROM (SELECT current_setting('log_line_prefix') AS s, replace(current_setting('log_destination'), ' ', '') AS d) x) THEN 'compliant' ELSE 'noncompliant' END" 2>/dev/null) || exit 1; printf '%s\n' "$out"

Expected output: compliant

How it is fixed

Fix method: SQL statement

shell

psql -X -U "${PGUSER:-postgres}" -c "ALTER SYSTEM SET log_line_prefix = '%m [%p]: [%l-1] db=%d,user=%u,app=%a,client=%h '" -c "SELECT pg_reload_conf()"

Properties

Operating systems: Any
Tags: postgresdatabaselogging
Reference: CIS PostgreSQL 18 Benchmark v1.0.0 - 3.1.24 Ensure 'log_line_prefix' is set correctly

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target postgres