OpenSSL: Null pointer deref in X509_issuer_and_serial_hash() (CVE-2021-23841) - Windows

# Copyright (C) 2021 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

CPE = "cpe:/a:openssl:openssl";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.145404");
  script_version("2021-08-30T10:29:27+0000");
  script_tag(name:"last_modification", value:"2021-08-30 10:29:27 +0000 (Mon, 30 Aug 2021)");
  script_tag(name:"creation_date", value:"2021-02-17 05:46:27 +0000 (Wed, 17 Feb 2021)");
  script_tag(name:"cvss_base", value:"4.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2021-07-20 23:15:00 +0000 (Tue, 20 Jul 2021)");

  script_cve_id("CVE-2021-23841");

  script_tag(name:"qod_type", value:"remote_banner");

  script_tag(name:"solution_type", value:"VendorFix");

  script_name("OpenSSL: Null pointer deref in X509_issuer_and_serial_hash() (CVE-2021-23841) - Windows");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("Denial of Service");
  script_dependencies("gb_openssl_consolidation.nasl", "os_detection.nasl");
  script_mandatory_keys("openssl/detected", "Host/runs_windows");

  script_tag(name:"summary", value:"OpenSSL is prone to a denial of service (DoS) vulnerability.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");

  script_tag(name:"insight", value:"The OpenSSL public API function X509_issuer_and_serial_hash() attempts to
  create a unique hash value based on the issuer and serial number data contained within an X509 certificate.
  However it fails to correctly handle any errors that may occur while parsing the issuer field (which might
  occur if the issuer field is maliciously constructed).");

  script_tag(name:"impact", value:"This vulnerability may subsequently result in a NULL pointer deref and a
  crash leading to a potential denial of service attack.");

  script_tag(name:"affected", value:"OpenSSL version 1.0.2x and prior and 1.1.1i and prior.");

  script_tag(name:"solution", value:"Update to version 1.0.2y, 1.1.1j or later. See the references for
  more details.");

  script_xref(name:"URL", value:"https://www.openssl.org/news/secadv/20210216.txt");

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if (isnull(port = get_app_port(cpe: CPE)))
  exit(0);

if (!infos = get_app_version_and_location(cpe: CPE, port: port, exit_no_version: TRUE))
  exit(0);

version = infos["version"];
location = infos["location"];

if (version_is_less(version: version, test_version: "1.0.2y")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "1.0.2y / 1.1.1j", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

if (version_in_range(version: version, test_version: "1.1.0", test_version2: "1.1.1i")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "1.1.1j", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

exit(99);