Factory Interface Network Service (FINS) Detection (UDP)

# SPDX-FileCopyrightText: 2017 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.140538");
  script_version("2023-09-19T05:06:03+0000");
  script_tag(name:"last_modification", value:"2023-09-19 05:06:03 +0000 (Tue, 19 Sep 2023)");
  script_tag(name:"creation_date", value:"2017-11-24 15:03:31 +0700 (Fri, 24 Nov 2017)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");

  script_tag(name:"qod_type", value:"remote_banner");

  script_name("Factory Interface Network Service (FINS) Detection (UDP)");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("Service detection");
  script_require_udp_ports(9600);

  script_tag(name:"summary", value:"UDP based detection of services supporting the Factory Interface
  Network Service (FINS) protocol.");

  script_tag(name:"insight", value:"FINS is a network protocol used by Omron PLCs. The FINS
  communications service was developed by Omron to provide a consistent way for PLCs and computers
  on various networks to communicate.");

  script_xref(name:"URL", value:"http://www.omron.com/");

  exit(0);
}

include("dump.inc");
include("host_details.inc");
include("port_service_func.inc");
include("misc_func.inc");

# based on https://github.com/digitalbond/Redpoint/blob/master/omronudp-info.nse

port = 9600;

if (!get_udp_port_state(port))
  exit(0);

soc = open_sock_udp(port);
if (!soc)
  exit(0);

# UDP read controller data command
ctrl_data_read = raw_string(0x80, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x63, 0x00, 0xef, 0x05, 0x01, 0x00);

send(socket: soc, data: ctrl_data_read);
recv = recv(socket: soc, length: 512);
close(soc);

if (!recv || (hexstr(recv[0]) != 'c0' && hexstr(recv[0]) != 'c1') || strlen(recv) < 49)
  exit(0);

# Some more information could be extracted (memory card type, program area size, etc) but this doesn't really
# add some valuable info for vulnerability scanning.
model = bin2string(ddata: substr(recv, 14, 43), noprint_replacement: '');
set_kb_item(name: "fins/model", value: model);
version = bin2string(ddata: substr(recv, 44, 48), noprint_replacement: '');
set_kb_item(name: "fins/version", value: version);

set_kb_item(name: "fins/detected", value: TRUE);

service_register(port: port, proto: "fins", ipproto: "udp");

report = 'A FINS service is running at this port.\n\nThe following information was extracted:\n\n' +
         "Controller Model:      " + model + '\n' +
         "Controller Version:    " + version;

log_message(port: port, data: report, proto: "udp");

exit(0);