Zabbix Server 7.4.x < 7.4.11 Authentication Bypass (ZBX-28071)

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

include('compat.inc');

if (description)
{
  script_id(338766);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/24");

  script_cve_id("CVE-2026-23933");

  script_name(english:"Zabbix Server 7.4.x < 7.4.11 Authentication Bypass (ZBX-28071)");

  script_set_attribute(attribute:"synopsis", value:
"A monitoring application installed on the remote host is affected by an authentication bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Zabbix Server installed on the remote host is 7.4.x prior to 7.4.11. It is, therefore, affected by an
authentication bypass vulnerability:

  - The cryptographic key used for signing Frontend sessions has been erroneously written to the database seed. In
    deployments that utilize both SAML authentication and guest users, the key can be used to forge valid session
    cookies, potentially leading to unauthorized access. (CVE-2026-23933)

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://support.zabbix.com/browse/ZBX-28071");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Zabbix version 7.4.11 or later.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/PR:N/UI:N/S:U/C:H/I:H/A:N");
  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:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-23933");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(259);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:zabbix:zabbix_server");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

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

  script_dependencies("zabbix_server_nix_installed.nbin");
  script_require_keys("installed_sw/Zabbix Server");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'requires': [{'scope': 'target', 'match': {'os': 'linux'}}],
  'checks': [
    {
      'product': {'name': 'Zabbix Server', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version':'7.4.0', 'fixed_version':'7.4.11'}
      ]
    }
  ]
};

var result = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_WARNING);
vdf::handle_check_and_report_errors(vdf_result:result);