Zyxel Router Buffer Overflow Vulnerability (DoS)

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#

include('compat.inc');

if (description)
{
  script_id(177214);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/28");

  script_cve_id("CVE-2023-27989");

  script_name(english:"Zyxel Router Buffer Overflow Vulnerability (DoS)");

  script_set_attribute(attribute:"synopsis", value:
"The router is affected by a buffer overflow / denial of service 
vulnerability.");
  script_set_attribute(attribute:"description", value:
"According to its model number and firmware revision, the remote Zyxel router is affected by a buffer overflow / denial
of service vulnerability, due to a flaw in the CGI program. An authenticated, remote attacker can exploit this issue,
via a crafted HTTP request, to cause the systeem to stop responding.");
  # https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-buffer-overflow-vulnerability-in-4g-lte-and-5g-nr-outdoor-routers
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f4fb8d5e");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the Zyxel firmware referenced in the advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-27989");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/06/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/06/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/06/13");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/h:zyxel");
  script_set_attribute(attribute:"enable_cgi_scanning", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("zyxel_router_detect_getbasicinfo.nbin");
  script_require_keys("www/zyxel_router");
  script_exclude_keys("Settings/disable_cgi_scanning");
  script_require_ports("Services/www", 80, 443);

  exit(0);
}

include('http.inc');
include('vcf_extras.inc');

var app_info = vcf::zyxel_router::get_app_info();

dbg::detailed_log(lvl:1, msg:'[plugin][app_info][dump_vcf][' + obj_rep(app_info.version) + ']'); 

# vendor says use this firmware
var lte7480_uglyfix     = "V1.00(ABRA.7)C0";
var lte7490_uglyfix     = "V1.00(ABQY.6)C0";
var nr7101_uglyfix      = "V1.00(ABUV.8)C0";
var neb_nr7101_uglyfix  = "V1.16(ACCC.0)C0";
var test_uglyfix        = "V1.00(ABZF.1)C1";

# let's make the firmware fix pretty
var lte7480_fix     = vcf::zyxel_router::transform_ver(firmware:lte7480_uglyfix);
var lte7490_fix     = vcf::zyxel_router::transform_ver(firmware:lte7490_uglyfix);
var nr7101_fix      = vcf::zyxel_router::transform_ver(firmware:nr7101_uglyfix);
var neb_nr7101_fix  = vcf::zyxel_router::transform_ver(firmware:neb_nr7101_uglyfix);
var test_fix        = vcf::zyxel_router::transform_ver(firmware:test_uglyfix);

# models is a list, each set as different constraints
var constraints = [
  { 'models': make_list("LTE7480-M804"),  'fixed_version': lte7480_fix,     'fixed_display': lte7480_uglyfix},
  { 'models': make_list("LTE7490-M904"),  'fixed_version': lte7490_fix,     'fixed_display': lte7490_uglyfix},
  { 'models': make_list("NR7101"),        'fixed_version': nr7101_fix,      'fixed_display': nr7101_uglyfix},
  { 'models': make_list("Nebula NR7101"), 'fixed_version': neb_nr7101_fix,  'fixed_display': neb_nr7101_uglyfix},
  { 'models': make_list("NR7103"),        'fixed_version': test_fix,        'fixed_display': test_uglyfix}
];

vcf::zyxel_router::check_version_and_report(
    app_info:app_info,
    constraints:constraints,
    severity:SECURITY_WARNING
);