Fortinet FortiWeb - Padding oracle in cookie encryption (FG-IR-21-126)

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

include('compat.inc');

if (description)
{
  script_id(171887);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/03/10");

  script_cve_id("CVE-2021-43074");
  script_xref(name:"IAVA", value:"2023-A-0110-S");

  script_name(english:"Fortinet FortiWeb - Padding oracle in cookie encryption (FG-IR-21-126)");

  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-21-126 advisory.

  - An improper verification of cryptographic signature vulnerability [CWE-347] in FortiOS,FortiWeb,
    FortiProxy and FortiSwitchmay allow an attackerto decrypt portions of the administrative session
    management cookie if able to intercept the latter.

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-21-126");
  script_set_attribute(attribute:"solution", value:
"Upgrade to FortiWeb version 6.3.17 / 7.0.0 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N");
  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:L/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-43074");

  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:"2023/02/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/02/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/02/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:fortinet:fortiproxy");
  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) 2023 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.inc');
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' : '6.0', 'fixed_version' : '6.3.17' },
  { 'min_version' : '6.4', 'fixed_version' : '7.0.0' }
];

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