Fortinet FortiWeb Buffer overflow in TFTP client library of CLI (FG-IR-21-173)

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

include('compat.inc');

if (description)
{
  script_id(209819);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/02/14");

  script_cve_id("CVE-2021-42757");
  script_xref(name:"IAVA", value:"2021-A-0574-S");

  script_name(english:"Fortinet FortiWeb Buffer overflow in TFTP client library of CLI (FG-IR-21-173)");

  script_set_attribute(attribute:"synopsis", value:
"Fortinet Firewall is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The version of FortiWeb installed on the remote host is prior to tested version. It is, therefore, affected by a
vulnerability as referenced in the FG-IR-21-173 advisory.

  - A buffer overflow [CWE-121] in the TFTP client library of FortiOS before 6.4.7 and FortiOS 7.0.0 through
    7.0.2, may allow an authenticated local attacker to achieve arbitrary code execution via specially crafted
    command line arguments. (CVE-2021-42757)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://www.fortiguard.com/psirt/FG-IR-21-173");
  script_set_attribute(attribute:"solution", value:
"For 5.0.x / 5.1.x / 5.2.x / 5.3.x / 5.4.x / 5.5.x / 5.6.x / 5.7.x / 5.8.x / 5.9.x / 6.0.x / 6.1.x / 6.2.x, see vendor
advisory. For 6.3.x, upgrade to FortiWeb version 6.3.17 or later. For 6.4.x, upgrade to FortiWeb version 6.4.2 or later.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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-2021-42757");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/12/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/10/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:fortinet:fortiweb");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Firewalls");

  script_copyright(english:"This script is Copyright (C) 2024-2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("fortinet_version.nbin");
  script_require_keys("Host/Fortigate/model", "Host/Fortigate/version");

  exit(0);
}

include('vcf_extras_fortios.inc');

var app_name = 'FortiWeb';
var app_info = vcf::get_app_info(app:app_name, kb_ver:'Host/Fortigate/version');
vcf::fortios::verify_product_and_model(product_name:app_name);

var constraints = [
  { 'min_version' : '5.0', 'fixed_version' : '5.0.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.1', 'fixed_version' : '5.1.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.2', 'fixed_version' : '5.2.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.3', 'fixed_version' : '5.3.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.4', 'fixed_version' : '5.4.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.5', 'fixed_version' : '5.5.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.6', 'fixed_version' : '5.6.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.7', 'fixed_version' : '5.7.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.8', 'fixed_version' : '5.8.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '5.9', 'fixed_version' : '5.9.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '6.0', 'fixed_version' : '6.0.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '6.1', 'fixed_version' : '6.1.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '6.2', 'fixed_version' : '6.2.999999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '6.3.0', 'max_version' : '6.3.16', 'fixed_version' : '6.3.17' },
  { 'min_version' : '6.4.0', 'max_version' : '6.4.1', 'fixed_version' : '6.4.2' }
];

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