# Author: Austin Taylor and Justin Henderson
# Email: email@austintaylor.io
# Last Update: 12/20/2017
# Version 0.3
# Description: Take in nessus reports from vulnWhisperer and pumps into logstash


input {
  file {
    path => "/opt/VulnWhisperer/data/nessus/**/*"
    mode => "read"
    start_position => "beginning"
    file_completed_action => "delete"
    tags => "nessus"
  }
  file {
    path => "/opt/VulnWhisperer/data/tenable/*.csv"
    mode => "read"
    start_position => "beginning"
    file_completed_action => "delete"
    tags => "tenable"
  }
}

filter {
  if "nessus" in [tags] or "tenable" in [tags] {
    # Drop the header column
    if [message] =~ "^Plugin ID" { drop {} }

    csv {
      # columns => ["plugin_id", "cve", "cvss", "risk", "asset", "protocol", "port", "plugin_name", "synopsis", "description", "solution", "see_also", "plugin_output"]
      columns => ["plugin_id", "cve", "cvss", "risk", "asset", "protocol", "port", "plugin_name", "synopsis", "description", "solution", "see_also", "plugin_output", "asset_uuid", "vulnerability_state", "ip", "fqdn", "netbios", "operating_system", "mac_address", "plugin_family", "cvss_base", "cvss_temporal", "cvss_temporal_vector", "cvss_vector", "cvss3_base", "cvss3_temporal", "cvss3_temporal_vector", "cvss3_vector", "system_type", "host_start", "host_end"]
      separator => ","
      source => "message"
    }

    ruby {
        code => "if event.get('description')
                    event.set('description', event.get('description').gsub(92.chr + 'n', 10.chr).gsub(92.chr + 'r', 13.chr))
                end
                 if event.get('synopsis')
                    event.set('synopsis', event.get('synopsis').gsub(92.chr + 'n', 10.chr).gsub(92.chr + 'r', 13.chr))
                end
                 if event.get('solution')
                    event.set('solution', event.get('solution').gsub(92.chr + 'n', 10.chr).gsub(92.chr + 'r', 13.chr))
                end
                 if event.get('see_also')
                    event.set('see_also', event.get('see_also').gsub(92.chr + 'n', 10.chr).gsub(92.chr + 'r', 13.chr))
                end
                 if event.get('plugin_output')
                    event.set('plugin_output', event.get('plugin_output').gsub(92.chr + 'n', 10.chr).gsub(92.chr + 'r', 13.chr))
                end"
    }

    #If using filebeats as your source, you will need to replace the "path" field to "source"
    # Remove when scan name is included in event (current method is error prone)
    grok {
      match => { "path" => "(?<scan_name>[a-zA-Z0-9_.\-]+)_%{INT:scan_id}_%{INT:history_id}_%{INT:last_updated}.csv$" }
      tag_on_failure => []
    }

    # TODO remove when @timestamp is included in event
    date {
      match => [ "last_updated", "UNIX" ]
      target => "@timestamp"
      remove_field => ["last_updated"]
    }

    if [risk] == "None" {
      mutate { add_field => { "risk_number" => 0 }}
    }
    if [risk] == "Low" {
      mutate { add_field => { "risk_number" => 1 }}
    }
    if [risk] == "Medium" {
      mutate { add_field => { "risk_number" => 2 }}
    }
    if [risk] == "High" {
      mutate { add_field => { "risk_number" => 3 }}
    }
    if [risk] == "Critical" {
      mutate { add_field => { "risk_number" => 4 }}
    }

    if ![cve] or [cve] == "nan" {
      mutate { remove_field => [ "cve" ] }
    }
    if ![cvss] or [cvss] == "nan" {
      mutate { remove_field => [ "cvss" ] }
    }
    if ![cvss_base] or [cvss_base] == "nan" {
      mutate { remove_field => [ "cvss_base" ] }
    }
    if ![cvss_temporal] or [cvss_temporal] == "nan" {
      mutate { remove_field => [ "cvss_temporal" ] }
    }
    if ![cvss_temporal_vector] or [cvss_temporal_vector] == "nan" {
      mutate { remove_field => [ "cvss_temporal_vector" ] }
    }
    if ![cvss_vector] or [cvss_vector] == "nan" {
      mutate { remove_field => [ "cvss_vector" ] }
    }
    if ![cvss3_base] or [cvss3_base] == "nan" {
      mutate { remove_field => [ "cvss3_base" ] }
    }
    if ![cvss3_temporal] or [cvss3_temporal] == "nan" {
      mutate { remove_field => [ "cvss3_temporal" ] }
    }
    if ![cvss3_temporal_vector] or [cvss3_temporal_vector] == "nan" {
      mutate { remove_field => [ "cvss3_temporal_vector" ] }
    }
    if ![description] or [description] == "nan" {
      mutate { remove_field => [ "description" ] }
    }
    if ![mac_address] or [mac_address] == "nan" {
      mutate { remove_field => [ "mac_address" ] }
    }
    if ![netbios] or [netbios] == "nan" {
      mutate { remove_field => [ "netbios" ] }
    }
    if ![operating_system] or [operating_system] == "nan" {
      mutate { remove_field => [ "operating_system" ] }
    }
    if ![plugin_output] or [plugin_output] == "nan" {
      mutate { remove_field => [ "plugin_output" ] }
    }
    if ![see_also] or [see_also] == "nan" {
      mutate { remove_field => [ "see_also" ] }
    }
    if ![synopsis] or [synopsis] == "nan" {
      mutate { remove_field => [ "synopsis" ] }
    }
    if ![system_type] or [system_type] == "nan" {
      mutate { remove_field => [ "system_type" ] }
    }

    mutate {
      remove_field => [ "message" ]
      add_field => { "risk_score" => "%{cvss}" }
    }
    mutate {
      convert => { "risk_score" => "float" }
    }
    if [risk_score] == 0 {
      mutate {
        add_field => { "risk_score_name" => "info" }
      }
    }
    if [risk_score] > 0 and [risk_score] < 3 {
      mutate {
        add_field => { "risk_score_name" => "low" }
      }
    }
    if [risk_score] >= 3 and [risk_score] < 6 {
      mutate {
        add_field => { "risk_score_name" => "medium" }
      }
    }
    if [risk_score] >=6 and [risk_score] < 9 {
      mutate {
        add_field => { "risk_score_name" => "high" }
      }
    }
    if [risk_score] >= 9 {
      mutate {
        add_field => { "risk_score_name" => "critical" }
      }
    }
  }
}

output {
  if "nessus" in [tags] or "tenable" in [tags]{
    stdout {
      codec => dots
    }
    elasticsearch {
      hosts => [ "elasticsearch:9200" ]
      index => "logstash-vulnwhisperer-%{+YYYY.MM}"
    }
  }
}