Zabbix Server 7.0.x < 7.0.29 / 7.4.x < 7.4.13 Authentication Bypass (ZBX-28196)

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

include('compat.inc');

if (description)
{
  script_id(364175);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/09");

  script_cve_id("CVE-2026-59786");

  script_name(english:"Zabbix Server 7.0.x < 7.0.29 / 7.4.x < 7.4.13 Authentication Bypass (ZBX-28196)");

  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 7.0.x prior to 7.0.29, or 7.4.x prior to 7.4.13. It is,
therefore, affected by an authentication bypass vulnerability:

  - Zabbix Server and Proxy accept the active agent heartbeat message regardless of the configured PSK or
    certificate authentication. This means someone with access to the Zabbix trapper port can report an arbitrary
    host using an active agent as available, resulting in a loss of integrity. (CVE-2026-59786)

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-28196");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Zabbix version 7.0.29, 7.4.13 or later.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/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:L/PR:N/UI:N/S:U/C:N/I:L/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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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-2026-59786");

  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:"2026/10/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/08");

  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':'7.0.0', 'fixed_version':'7.0.29'},
        {'min_version':'7.4.0', 'fixed_version':'7.4.13'}
      ]
    }
  ]
};

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