Unix: Command Output

Description

The Unix: Command Output test executes a shell command and evaluates the lines of output.

The shellcommand_object element is used by a shellcommand_test to define the shell command being run.

The shellcommand_state element specifies the output value to check.

Technical Details

Artifact Parameters

unix.command_output_v1

Name	Type	Description
command	string	The command to run.

Supported Test Types

Equals

Pattern Match

Pattern Not Match

Null Test

Test Type Parameters

equals
pattern match
pattern not match

Name	Type	Description
value	string	The value to be tested.
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

null_test_v1

Name	Type	Description
N/A

Generated Content

equals
pattern match
pattern not match

XCCDF+AE

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

<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>[RECOMMENDATION-TITLE</ae:title>
      <ae:artifact type="[ARTIFACT-TYPE-NAME]">
        <ae:parameters>
          <ae:parameter dt="string" name="command">[command.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>

SCAP

XCCDF

For unix.command_output_v1 equals, pattern match, and pattern not match artifacts, an XCCDF Value element is generated.

<Value
  id="xccdf_org.cisecurity.benchmarks_value_[ARTIFACT-OVAL-ID]_var"
  type="[type.value]"
  operator="[operator.value]">
  <title>[RECOMMENDATION-TITLE]</title>
  <description>This value is used in Rule: [RECOMMENDATION-TITLE]</description>
  <value>[value.value]</value>
</Value>

For unix.command_output_v1 equals, pattern match, and pattern not match artifacts, the XCCDF check looks like this.

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

OVAL

Test

<shellcommand_test
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#cmd"
  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]" />
  <state state_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:ste:[ARTIFACT-OVAL-ID]" />
</shellcommand_test>

Object

<shellcommand_object
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#cmd"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:obj:[ARTIFACT-OVAL-ID]"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <command>[command.value]</command>
  <line_selection operation="pattern match">.+</line_selection>
</shellcommand_object>

State

<shellcommand_state
  xmlns="http://oval.mitre.org/XMLSchema/oval-definitions-5#cmd"
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:ste:[ARTIFACT-OVAL-ID]"
  comment="[ARTIFACT-TITLE]"
  version="1">
  <stdout_line
    entity_check="at least one"
    operation="[operation.value]"
    var_ref="oval:org.cisecurity.benchmarks.[PLATFORM]:var:[ARTIFACT-OVAL-ID]" />
</shellcommand_state>

Variable

<external_variable
  id="oval:org.cisecurity.benchmarks.[PLATFORM]:var:[ARTIFACT-OVAL-ID]"
  datatype="[datatype.value]"
  version="1"
  comment="This value is used in [RECOMMENDATION-TITLE]" />

YAML

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

JSON

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