Samba Share Escape Vulnerability (CVE-2021-43566)

# Copyright (C) 2022 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:samba:samba";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.117876");
  script_version("2022-01-24T03:04:40+0000");
  script_tag(name:"last_modification", value:"2022-01-24 03:04:40 +0000 (Mon, 24 Jan 2022)");
  script_tag(name:"creation_date", value:"2022-01-10 14:17:13 +0000 (Mon, 10 Jan 2022)");
  script_tag(name:"cvss_base", value:"1.2");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:N/C:N/I:P/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2022-01-20 18:17:00 +0000 (Thu, 20 Jan 2022)");

  script_cve_id("CVE-2021-43566");

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

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

  script_name("Samba Share Escape Vulnerability (CVE-2021-43566)");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2022 Greenbone Networks GmbH");
  script_family("General");
  script_dependencies("smb_nativelanman.nasl", "gb_samba_detect.nasl");
  script_mandatory_keys("samba/smb_or_ssh/detected");

  script_tag(name:"summary", value:"Samba is prone to a share escape vulnerability.");

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

  script_tag(name:"insight", value:"Samba is vulnerable to a malicious client using an SMB1 or NFS
  symlink race to allow a directory to be created in an area of the server file system not exported
  under the share definition. Note that SMB1 has to be enabled, or the share also available via NFS
  in order for this attack to succeed.");

  script_tag(name:"affected", value:"Samba versions prior to 4.13.16.");

  script_tag(name:"solution", value:"Update to version 4.13.16 or later.");

  script_xref(name:"URL", value:"https://www.samba.org/samba/history/samba-4.13.16.html");
  script_xref(name:"URL", value:"https://www.samba.org/samba/security/CVE-2021-43566.html");

  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: "4.13.16")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "4.13.16", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

exit(99);