OpenSSL: Alternative Chains Certificate Forgery (20150709) - Linux

# 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("1.3.6.1.4.1.25623.1.0.112977");
  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:"2021-08-17 06:07:11 +0000 (Tue, 17 Aug 2021)");
  script_tag(name:"cvss_base", value:"6.4");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2018-11-30 21:30:00 +0000 (Fri, 30 Nov 2018)");

  script_cve_id("CVE-2015-1793");

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

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

  script_name("OpenSSL: Alternative Chains Certificate Forgery (20150709) - Linux");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("General");
  script_dependencies("gb_openssl_consolidation.nasl", "os_detection.nasl");
  script_mandatory_keys("openssl/detected", "Host/runs_unixoide");

  script_tag(name:"summary", value:"OpenSSL is prone to certificate forgery.");

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

  script_tag(name:"insight", value:"An error in the implementation of the alternative certificate
  chain logic could allow an attacker to cause certain checks on untrusted certificates to be
  bypassed, such as the CA flag, enabling them to use a valid leaf certificate to act as a CA
  and 'issue' an invalid certificate.");

  script_tag(name:"affected", value:"OpenSSL 1.0.1n through 1.0.1o and 1.0.2b through 1.0.2c.");

  script_tag(name:"solution", value:"Update to version 1.0.1p, 1.0.2d or later.");

  script_xref(name:"URL", value:"https://www.openssl.org/news/secadv/20150709.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_in_range(version: version, test_version: "1.0.1n", test_version2: "1.0.1o")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "1.0.1p", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

if (version_in_range(version: version, test_version: "1.0.2b", test_version2: "1.0.2c")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "1.0.2d", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

exit(99);