NetScaler ADC and NetScaler Gateway Multiple Vulnerabilities (CTX696939)

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

include('compat.inc');

if (description)
{
  script_id(338328);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/21");

  script_cve_id("CVE-2026-19489", "CVE-2026-19490");

  script_name(english:"NetScaler ADC and NetScaler Gateway Multiple Vulnerabilities (CTX696939)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote NetScaler ADC (formerly Citrix ADC) or NetScaler Gateway (formerly Citrix Gateway) device is
13.1 prior to 13.1-63.21, or 14.1 prior to 14.1-73.32, or 13.1-FIPS/NDcPP prior to 13.1-37.277, or 14.1-FIPS
prior to 14.1-73.32. It is, therefore, affected by multiple vulnerabilities:

  - Authentication bypass using an alternate path in NetScaler ADC and NetScaler Gateway when the appliance
    is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or an AAA virtual server, subject to
    version-specific SAML action requirements. (CVE-2026-19490)

  - Memory overflow vulnerability in NetScaler ADC and NetScaler Gateway leading to unpredictable behavior or
    Denial of Service if SIP ALG (Session Initiation Protocol Application Layer Gateway) is enabled on a
    Large Scale NAT (LSN) group configuration. (CVE-2026-19489)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported
version number.");
  # https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696939
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d6e67cff");
  script_set_attribute(attribute:"solution", value:
"Upgrade to NetScaler ADC or NetScaler Gateway version 13.1-63.21, 14.1-73.32, 13.1-37.277-FIPS, 13.1-37.277-NDcPP, or 14.1-73.32-FIPS or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:L/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-19490");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(119, 288);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/20");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:citrix:netscaler_gateway");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:citrix:netscaler_application_delivery_controller");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("citrix_netscaler_detect.nbin");
  script_require_keys("Host/NetScaler/Detected");

  exit(0);
}

include('vcf_extras_netscaler.inc');

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

# We cannot test for the full vulnerable condition
if (report_paranoia < 2) audit(AUDIT_POTENTIAL_VULN, 'Citrix NetScaler', app_info.display_version);

var constraints;

if (app_info['fips_status'] == 1)
  constraints = [
    {'fips':TRUE, 'min_version': '13.1', 'fixed_version': '13.1.37.277', 'fixed_display':'13.1-37.277-FIPS/NDcPP'},
    {'fips':TRUE, 'min_version': '14.1', 'fixed_version': '14.1.73.32', 'fixed_display':'14.1-73.32-FIPS'}
  ];
else
  constraints = [
    {'min_version': '13.1', 'fixed_version': '13.1.63.21', 'fixed_display': '13.1-63.21'},
    {'min_version': '14.1', 'fixed_version': '14.1.73.32', 'fixed_display': '14.1-73.32'}
  ];

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