TELESTAR-DIGITAL GmbH Multiple Internet Radio Undocumented Telnet Service / Default Credentials (Telnet)

# Copyright (C) 2019 Greenbone Networks GmbH
#
# 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("1.3.6.1.4.1.25623.1.0.108647");
  script_version("2023-03-01T10:20:05+0000");
  script_cve_id("CVE-2019-13473");
  script_tag(name:"cvss_base", value:"10.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_tag(name:"last_modification", value:"2023-03-01 10:20:05 +0000 (Wed, 01 Mar 2023)");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-08-27 17:36:00 +0000 (Thu, 27 Aug 2020)");
  script_tag(name:"creation_date", value:"2019-09-17 11:03:13 +0000 (Tue, 17 Sep 2019)");
  script_name("TELESTAR-DIGITAL GmbH Multiple Internet Radio Undocumented Telnet Service / Default Credentials (Telnet)");
  script_category(ACT_ATTACK);
  script_family("Default Accounts");
  script_copyright("Copyright (C) 2019 Greenbone Networks GmbH");
  script_dependencies("telnetserver_detect_type_nd_version.nasl", "gb_default_credentials_options.nasl");
  script_require_ports("Services/telnet", 23);
  script_mandatory_keys("telnet/mult_dvr_or_radio/detected");
  script_exclude_keys("default_credentials/disable_default_account_checks");

  script_xref(name:"URL", value:"https://www.vulnerability-lab.com/get_content.php?id=2183");
  script_xref(name:"URL", value:"https://www.vulnerability-db.com/?q=articles/2019/09/09/imperial-dabman-internet-radio-undocumented-telnetd-code-execution");

  script_tag(name:"summary", value:"The internet radio products of TELESTAR-DIGITAL GmbH have an undocumented Telnet service
  with default credentials enabled.");

  script_tag(name:"affected", value:"TELESTAR Bobs Rock Radio, Dabman D10, Dabman i30 Stereo, Imperial i110, Imperial i150,
  Imperial i200, Imperial i200-cd, Imperial i400, Imperial i450, Imperial i500-bt, and Imperial i600 devices are known to be
  affected. Other devices and vendors might be affected as well.");

  script_tag(name:"impact", value:"This issue may only be exploited by an attacker a root shell on the device.");

  script_tag(name:"vuldetect", value:"Connect to the Telnet service and try to login with default credentials.");

  script_tag(name:"insight", value:"It was possible to login with the telnet credentials 'root:password'.");

  script_tag(name:"solution", value:"The vendor has released the firmware update TN81HH96-g102h-g103**a*-fb21a-3624
  which is disabling the telnet service and removing the default password.");

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

  exit(0);
}

if( get_kb_item( "default_credentials/disable_default_account_checks" ) )
  exit( 0 );

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

port = telnet_get_port( default:23 );
banner = telnet_get_banner( port:port );
if( ! banner || "(none) login: " >!< banner )
  exit( 0 );

login = "root";
pass = "password";

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

res = telnet_negotiate( socket:soc );

if( res && "(none) login: " >< res ) {

  send( socket:soc, data:login + '\r\n' );
  sleep( 3 ); # nb: The devices requires quite some time to answer so wait for a few seconds.
  res = recv( socket:soc, length:128 );

  if( res && "Password:" >< res ) {

    send( socket:soc, data:pass + '\r\n' );
    sleep( 3 );
    res = recv( socket:soc, length:1024 );

    if( res && "BusyBox" >< res && "built-in shell" >< res ) {
      VULN = TRUE;
      report = 'It was possible to login via Telnet using the following credentials:\n\n';
      report += 'Login: ' + login + ', Password: ' + pass;
    }
  }
}

telnet_close_socket( socket:soc, data:res );

if( VULN ) {
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );