Fortinet FortiGate ZebOS routing remote shell service enabled (FG-IR-15-020)

# Copyright (C) 2017 Greenbone Networks GmbH
# 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-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.140112");
  script_version("2021-07-12T08:06:48+0000");
  script_tag(name:"cvss_base", value:"9.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_cve_id("CVE-2015-7361");

  script_name("Fortinet FortiGate ZebOS routing remote shell service enabled (FG-IR-15-020)");

  script_xref(name:"URL", value:"https://www.fortiguard.com/psirt/FG-IR-15-020");

  script_tag(name:"vuldetect", value:"Open a connection to port 2650 and execute the `show version`
  command.");

  script_tag(name:"insight", value:"A remote attacker may access the internal ZebOS shell of FortiOS
  5.2.3 without authentication on the HA dedicated management interface only.

  Only FortiGates configured with HA *and* with an enabled HA dedicated management interface are
  vulnerable.");

  script_tag(name:"solution", value:"Update FortiOS to version 5.2.4 or later.");

  script_tag(name:"summary", value:"The Fortinet FortiGate device has the ZebOS routing remote shell
  service enabled.");

  script_tag(name:"affected", value:"FortiGate version 5.2.3 only.");

  script_tag(name:"solution_type", value:"VendorFix");

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

  script_tag(name:"last_modification", value:"2021-07-12 08:06:48 +0000 (Mon, 12 Jul 2021)");
  script_tag(name:"creation_date", value:"2017-01-02 12:27:55 +0100 (Mon, 02 Jan 2017)");
  script_category(ACT_ATTACK);
  script_family("Gain a shell remotely");
  script_copyright("Copyright (C) 2017 Greenbone Networks GmbH");
  script_dependencies("find_service.nasl");
  script_require_ports("Services/zebos_routing_shell");

  exit(0);
}

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

if( ! port = service_get_port( proto:"zebos_routing_shell", nodefault:TRUE ) )
  exit( 0 );

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

recv = recv( socket:soc, length:128 );

if( "ZebOS" >!< recv ) {
  close( soc );
  exit( 99 );
}

send( socket:soc, data:'show version\n' );
recv = recv( socket:soc, length:512 );

close( soc );

if( "ZebOS version" >< recv && "IP Infusion Inc" >< recv ) {
  report = 'The ZebOS routing remote shell is accessible at this port without authentication. Running "show version" gives the following output:\n' + recv + '\n';
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );