V-72841

control "V-72841" do
  title "PostgreSQL must be configured to prohibit or restrict the use of
        organization-defined functions, ports, protocols, and/or services, as
        defined in the PPSM CAL and vulnerability assessments."
  desc  "In order to prevent unauthorized connection of devices, unauthorized
        transfer of information, or unauthorized tunneling (i.e., embedding of
        data types within data types), organizations must disable or restrict
        unused or unnecessary physical and logical ports/protocols/services on
        information systems.

        Applications are capable of providing a wide variety of functions and
        services. Some of the functions and services provided by default may
        not be necessary to support essential organizational operations.
        Additionally, it is sometimes convenient to provide multiple services
        from a single component (e.g., email and web services); however, doing
        so increases risk over limiting the services provided by any one component.

        To support the requirements and principles of least functionality, the
        application must support the organizational requirements providing only
        essential capabilities and limiting the use of ports, protocols, and/or
        services to only those required, authorized, and approved to conduct
        official business or to address authorized quality of life issues.

        Database Management Systems using ports, protocols, and services deemed
        unsafe are open to attack through those ports, protocols, and services.
        This can allow unauthorized access to the database and through the
        database to other components of the information system."
  impact 0.5
  tag "severity": "medium"

  tag "gtitle": "SRG-APP-000142-DB-000094"
  tag "gid": "V-72841"
  tag "rid": "SV-87493r1_rule"
  tag "stig_id": "PGS9-00-000100"
  tag "cci": "CCI-000382"
  tag "nist": ["CM-7 b", "Rev_4"]
  tag "cci": "CCI-001762"
  tag "nist": ["CM-7 (1) (b)", "Rev_4"]

  tag "check": "As the database administrator, run the following SQL:

  $ psql -c \"SHOW port\"

  If the currently defined port configuration is deemed prohibited, this is a
  finding."

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

  To change the listening port of the database, as the database administrator,
  change the following setting in postgresql.conf:

  $ sudo su - postgres
  $ vi $PGDATA/postgresql.conf

  Change the port parameter to the desired port.

  Next, restart the database:

  $ sudo su - postgres
  # SYSTEMD SERVER ONLY
  $ systemctl restart postgresql-9.5
  # INITD SERVER ONLY
  $ service postgresql-9.5 restart

  Note: psql uses the default port 5432 by default. This can be changed by
  specifying the port with psql or by setting the PGPORT environment variable:

  $ psql -p 5432 -c \"SHOW port\"
  $ export PGPORT=5432"

  sql = postgres_session(PG_DBA, PG_DBA_PASSWORD, PG_HOST)

  describe sql.query('SHOW port;', [PG_DB]) do
    its('output') { should eq PG_PORT }
  end

  describe port(PG_PORT) do
    it { should be_listening }
    its('processes') { should include 'postgres' }
  end
end