Zyxel USG FLEX H Series Firewall < 1.32 Privilege Escalation

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

include('compat.inc');

if (description)
{
  script_id(237022);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/05/21");

  script_cve_id("CVE-2025-1732");
  script_xref(name:"IAVA", value:"2025-A-0295");

  script_name(english:"Zyxel USG FLEX H Series Firewall < 1.32 Privilege Escalation");

  script_set_attribute(attribute:"synopsis", value:
"The remote security gateway is affected by multiple privilege escalation vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"Firmware version of the Zyxel USG is less than uOS 1.32. This means the Zyxel device is vulnerable to a
privilege escalation vulnerability. The improper privilege management vulnerability in the recovery function
of certain USG FLEX H series uOS firmware versions could allow an authenticated local attacker with 
administrator privileges to upload a crafted configuration file and escalate privileges on a vulnerable 
device.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-incorrect-permission-assignment-and-improper-privilege-management-vulnerabilities-in-usg-flex-h-series-firewalls-04-22-2025
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a10e5b38");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Zyxel USG uOS 1.32 or later.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:M/C:C/I:C/A: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_attribute(attribute:"cvss_score_source", value:"CVE-2025-1732");

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/04/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/04/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/05/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:zyxel:usg_flex");
  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) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("zyxel_usg_detect.nbin");
  script_require_keys("installed_sw/Zyxel Unified Security Gateway (USG)");
  script_require_ports("Host/Zyxel/USG/uos");

  exit(0);
}

include('vcf.inc');

var app = 'Zyxel Unified Security Gateway (USG)';

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

var model = app_info['Model'];
var constraints = [];

if(empty_or_null(model))
  audit(AUDIT_OS_CONF_UNKNOWN, 'Zyxel device');

if ('USG FLEX' >< model && 'H' >< model) 
  constraints = [{'fixed_version' : '1.32'}];
else 
  audit(AUDIT_NOT_INST, 'Zyxel USG FLEX H Series Device');

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