V-73027

control "V-73027" do
  title "PostgreSQL must require users to reauthenticate when organization-defined
circumstances or situations require reauthentication."
  desc  "The DoD standard for authentication of an interactive user is the
presentation of a Common Access Card (CAC) or other physical token bearing a valid,
current, DoD-issued Public Key Infrastructure (PKI) certificate, coupled with a
Personal Identification Number (PIN) to be entered by the user at the beginning of
each session and whenever reauthentication is required.

Without reauthentication, users may access resources or perform tasks for which they
do not have authorization.

When applications provide the capability to change security roles or escalate the
functional capability of the application, it is critical the user re-authenticate.

In addition to the reauthentication requirements associated with session locks,
organizations may require reauthentication of individuals and/or devices in other
situations, including (but not limited to) the following circumstances:

(i) When authenticators change;
(ii) When roles change;
(iii) When security categorized information systems change;
(iv) When the execution of privileged functions occurs;
(v) After a fixed period of time; or
(vi) Periodically.

Within the DoD, the minimum circumstances requiring reauthentication are privilege
escalation and role changes."
  impact 0.5
  tag "severity": "medium"
  tag "gtitle": "SRG-APP-000389-DB-000372"
  tag "gid": "V-73027"
  tag "rid": "SV-87679r1_rule"
  tag "stig_id": "PGS9-00-010100"
  tag "cci": "CCI-002038"
  tag "nist": ["IA-11", "Rev_4"]
  tag "check": "Determine all situations where a user must re-authenticate. Check if
the mechanisms that handle such situations use the following SQL:

To make a single user re-authenticate, the following must be present:

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE user='<username>'

To make all users re-authenticate, run the following:

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE user LIKE '%'

If the provided SQL does not force re-authentication, this is a finding."
  tag "fix": "Modify and/or configure PostgreSQL and related applications and tools
so that users are always required to reauthenticate when changing role or escalating
privileges.

To make a single user re-authenticate, the following must be present:

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE user='<username>'

To make all users re-authenticate, the following must be present:

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE user LIKE '%'"

  only_if { false }

end