Control: 3.10 Ensure that TLS CA certificate file permissions are set to 444 or more restrictively

Description

You should verify that the TLS CA certificate file (the file that is passed along with the -- tlscacert parameter) has permissions of 444 or is set more restrictively

The TLS CA certificate file should be protected from any tampering. It is used to authenticate the Docker server based on a given CA certificate. It must therefore have permissions of 444, or more restrictive permissions to ensure that the file cannot be modified by a less privileged user.

Remediation

The following command could be executed:

chmod 444 <path to TLS CA certificate file>

This sets the file permissions on the TLS CA file to 444.

Default Value

By default, the permissions for the TLS CA certificate file might not be 444. The default file permissions are governed by the operating system or user specific umask values.

Usage

Run the control in your terminal:

powerpipe control run docker_compliance.control.cis_v160_3_10

Snapshot and share results via Turbot Pipes:

powerpipe login
powerpipe control run docker_compliance.control.cis_v160_3_10 --share

SQL

This control uses a named query:

with os_output as (
  select
    btrim(stdout_output, E' \n\r\t') as os,
    _ctx ->> 'connection_name' as os_conn
  from
    exec_command
  where
    command = 'uname -s'
), hostname as (
  select
    btrim(stdout_output, E' \n\r\t') as host,
    _ctx ->> 'connection_name' as host_conn,
    _ctx
  from
    exec_command
  where
    command = 'hostname'
),

linux_output as (
  with json_value_cte as (
    select
      -- Use the colon as a "true" command that returns an empty string
      case when stdout_output = '' or (stdout_output::jsonb->>'tlscacert') is null then ':' else 'stat -c %a ' || (stdout_output::jsonb->>'tlscacert') end as key_value,
      _ctx ->> 'connection_name' as os_conn
    from
      exec_command,
      os_output
    where
      os_conn = _ctx ->> 'connection_name'
      and command = 'cat /etc/docker/daemon.json'
    order by
      key_value
  )
  select
    stdout_output,
    _ctx ->> 'connection_name' as conn
  from
    json_value_cte as a
  join
    exec_command
    on command = a.key_value
  where
    os_conn = _ctx ->> 'connection_name'
)
select
  host as resource,
  case
    when os.os ilike '%Darwin%' then 'skip'
    when o.stdout_output = '' then 'skip'
    when o.stdout_output like '%444%' then 'ok'
    else 'alarm'
  end as status,
  case
    when os.os ilike '%Darwin%' then host || ' /etc/docker/daemon.json does not exist on ' || os.os || ' OS.'
    when o.stdout_output = '' then host || ' TLS CA certificate file does not exist.'
    when o.stdout_output like '%444%' then host || ' TLS CA certificate file permissions are set to 444.'
    else host || ' TLS CA certificate file permissions are set to ' || (btrim(o.stdout_output, E' \n\r\t')) || '.'
  end as reason
  , h._ctx ->> 'connection_name' as connection_name
from
  hostname as h,
  os_output as os,
  linux_output as o
where
  os.os_conn = h.host_conn
  and h.host_conn = o.conn;

Control: 3.10 Ensure that TLS CA certificate file permissions are set to 444 or more restrictively

Description

Remediation

Default Value

Usage

SQL

Tags