Fortinet Fortigate Stack buffer overflow in WAD (FG-IR-26-161)

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

include('compat.inc');

if (description)
{
  script_id(334916);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/10");

  script_cve_id("CVE-2026-71407");
  script_xref(name:"IAVA", value:"2026-A-0738");

  script_name(english:"Fortinet Fortigate Stack buffer overflow in WAD (FG-IR-26-161)");

  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 Fortigate installed on the remote host is prior to tested version. It is, therefore, affected by a
vulnerability as referenced in the FG-IR-26-161 advisory.

  - A Stack-based Buffer Overflow vulnerability [CWE-121] vulnerability in Fortinet FortiOS 7.6.1 through
    7.6.6 may allow an unauthenticated attacker who can bypass stack protection and ASLR to execute arbitrary
    code or commands in the context of the WAD daemon via crafted sockets, only if the explicit proxy is
    configured with Kerberos authentication and SOCKS enabled. (CVE-2026-71407)

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-26-161");
  script_set_attribute(attribute:"solution", value:
"For 7.6.x, upgrade to Fortigate version 7.6.7 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/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:H/PR:N/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-2026-71407");

  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:"2026/08/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fortinet:fortios");
  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) 2026 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 = 'Fortigate';
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' : '7.6.1', 'max_version' : '7.6.6', 'fixed_version' : '7.6.7' }
];

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