libcurl 7.69.0 < 8.21.0 SSH Improper Host Validation

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

include('compat.inc');

if (description)
{
  script_id(323010);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/26");

  script_cve_id("CVE-2026-9547");
  script_xref(name:"IAVA", value:"2026-A-0627");

  script_name(english:"libcurl 7.69.0 < 8.21.0 SSH Improper Host Validation");

  script_set_attribute(attribute:"synopsis", value:
"The remote host has a program that is affected by an improper host validation vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of libcurl installed on the remote host is 7.69.0 prior to 8.21.0. It is, therefore, affected by
an improper host validation vulnerability:

  - When a libcurl-based application performs transfers via SCP or SFTP and utilizes the
    CURLOPT_SSH_KEYFUNCTION callback, it may silently accept an untrusted server. (CVE-2026-9547)

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://curl.se/docs/CVE-2026-9547.html");
  script_set_attribute(attribute:"solution", value:
"Upgrade libcurl to version 8.21.0 or later.");
  script_set_attribute(attribute:"agent", value:"all");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  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_attribute(attribute:"cvss_score_source", value:"CVE-2026-9547");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"asset_categories", value:"component");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:haxx:libcurl");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  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("libcurl_nix_installed.nbin", "libcurl_win_installed.nbin");
  script_require_keys("installed_sw/libcurl");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'checks': [
    {
      'product': {'name': 'libcurl', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '7.69.0', 'fixed_version': '8.21.0'}
      ]
    }
  ]
};

var res = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_HOLE);
vdf::handle_check_and_report_errors(vdf_result:res);