Linux: Auditd Rule

Description

The Linux: Auditd Rule test is used to check the contents of audit configuration and audit log files by looking at individual blocks of text.

The textfilecontent54_object element is used by an textfilecontent54_test to define the specific block(s) of text of a file(s) to be evaluated. The textfilecontent54_object will only collect regular files on UNIX systems.

The set of files to be evaluated may be identified with either a complete filepath or a path and filename. Only one of these options may be selected.

The textfilecontent54_state element contains entities that are used to check the file path and name, as well as the text block in question and the value of the subexpressions.

Technical Details

Artifact Parameters

linux.auditd_rule_v1

Name	Type	Description
check_existence	string	Defines how many items should be collected. Typically set to ‘at least one’.

NOTE: The check_existence parameter is governed by a constraint allowing only the following values:

at_least_one_exists
none_exist

Supported Test Types

Set Includes

Test Type Parameters

set.includes_v1

Name	Type	Description
value	string	The value included within the set of results.
data_type	string	The data type of the value.

NOTE: The data_type parameter is governed by a constraint allowing only the following values:

boolean
float
int
string
version
set

Generated Content

set.includes_v1

XCCDF+AE

This is what the AE check looks like, inside a Rule, in the XCCDF.

<xccdf:complex-check operator="AND">
  <xccdf:check system="https://benchmarks.cisecurity.org/ae/0.5">
    <xccdf:check-content>
      <ae:artifact_expression id="xccdf_org.cisecurity.benchmarks_ae_[SECTION-NUMBER]">
        <ae:artifact_oval_id>[ARTIFACT-OVAL-ID]</ae:artifact_oval_id>
        <ae:title>[ARTIFACT-TITLE]</ae:title>
        <ae:artifact type="[ARTIFACT-TYPE-NAME]">
          <ae:parameters>
            <ae:parameter dt="string" name="check_existence">[check_existence.value]</ae:parameter>
          </ae:parameters>
        </ae:artifact>
        <ae:test type="[TEST-TYPE-NAME]">
          <ae:parameters>
            <ae:parameter dt="string" name="value">[value.value]</ae:parameter>
            <ae:parameter dt="string" name="data_type">[data_type.value]</ae:parameter>
          </ae:parameters>
        </ae:test>
        <ae:profiles>
          <ae:profile idref="xccdf_org.cisecurity.benchmarks_profile_Level_2" />
        </ae:profiles>
      </ae:artifact_expression>
    </xccdf:check-content>
  </xccdf:check>
</xccdf:complex-check>

SCAP

XCCDF

For linux.auditd_rule_v1 set.includes_v1 artifacts, the XCCDF check looks like this. There is no Value element in the XCCDF for this artifact.

<check system="http://oval.mitre.org/XMLSchema/oval-definitions-5">
  <check-content-ref
    href="[BENCHMARK-TITLE]-oval.xml"
    name="oval:org.cisecurity.benchmarks.[PLATFORM]:def:[ARTIFACT-OVAL-ID]" />
</check>

OVAL

Test

<textfilecontent54_test
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#independent"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:tst:[ARTIFACT-OVAL-ID]"
  check_existence="at_least_one_exists"
  check="all"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <object object_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:obj:[ARTIFACT-OVAL-ID]" />
</textfilecontent54_test>

Object

<textfilecontent54_object
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#independent"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:obj:[ARTIFACT-OVAL-ID]"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <path>/etc/audit</path>
  <filename>auditd.rules</filename>
  <pattern
    datatype="[datatype.value]"
    operation="pattern match">
      [pattern.value]
  </pattern>
  <instance
    datatype="int"
    operation="equals">
      1
  </instance>
</textfilecontent54_object>

State

N/A

YAML

artifact-expression:
  artifact-unique-id: "[ARTIFACT-OVAL-ID]"
  artifact-title: "[ARTIFACT-TITLE]"
  artifact:
    type: "[ARTIFACT-TYPE-NAME]"
    parameters:
      - parameter:
          name: "check_existence"
          dt: "string"
          value: "[check_existence.value]"
  test:
    type: "[TEST-TYPE-NAME]"
    parameters:
      - parameter:
          name: "value"
          dt: "string"
          value: "[value.value]"
      - parameter:
          name: "data_type"
          dt: "string"
          value: "[data_type.value]"

JSON

{
  "artifact-expression": {
    "artifact-unique-id": "[ARTIFACT-OVAL-ID]",
    "artifact-title": "[ARTIFACT-TITLE]",
    "artifact": {
      "type": "[ARTIFACT-TYPE-NAME]",
      "parameters": [
        {
          "parameter": {
            "name": "check_existence",
            "type": "string",
            "value": "[check_existence.value]"
          }
        }
      ]
    },
    "test": {
      "type": "[TEST-TYPE-NAME]",
      "parameters": [
        {
          "parameter": {
            "name": "value",
            "type": "string",
            "value": "[value.value]"
          }
        },
        {
          "parameter": {
            "name": "data_type",
            "type": "string",
            "value": "[data_type.value]"
          }
        }
      ]
    }
  }
}