Microsoft Windows: Prevent the computer from joining a homegroup

# Copyright (C) 2018 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.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.109450");
  script_version("2022-08-31T10:10:28+0000");
  script_tag(name:"last_modification", value:"2022-08-31 10:10:28 +0000 (Wed, 31 Aug 2022)");
  script_tag(name:"creation_date", value:"2018-06-27 08:25:51 +0200 (Wed, 27 Jun 2018)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:S/C:N/I:N/A:N");
  script_tag(name:"qod", value:"97");
  script_name("Microsoft Windows: Prevent the computer from joining a homegroup");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2018 Greenbone Networks GmbH");
  script_family("Policy");
  script_dependencies("compliance_tests.nasl", "smb_reg_service_pack.nasl");
  script_mandatory_keys("Compliance/Launch");

  script_add_preference(name:"Value", type:"radio", value:"1;0", id:1);

  script_xref(name:"Policy", value:"CIS Microsoft Windows 10 Enterprise (Release 2004) Benchmark v1.9.1: 18.9.35.1 (L1) Ensure 'Prevent the computer from joining a homegroup' is set to 'Enabled'");
  script_xref(name:"Policy", value:"CIS Controls Version 7: 14.1 Segment the Network Based on Sensitivity");
  script_xref(name:"Policy", value:"CIS Controls Version 7: 14.2 Enable Firewall Filtering Between VLANs");
  script_xref(name:"URL", value:"https://www.microsoft.com/en-us/download/confirmation.aspx?id=25250");

  script_tag(name:"summary", value:"This policy setting specifies whether users can add computers to
a homegroup. By default, users can add their computer to a homegroup on a private network.

If you enable this policy setting, users cannot add computers to a homegroup. This policy setting
does not affect other network sharing features.

If you disable or do not configure this policy setting, users can add computers to a homegroup.
However, data on a domain-joined computer is not shared with the homegroup.

This policy setting is not configured by default.

You must restart the computer for this policy setting to take effect.

(C) 2015 Microsoft Corporation.");

  exit(0);
}

include("smb_nt.inc");
include("policy_functions.inc");
include("version_func.inc");

target_os = "Microsoft Windows 7 or later";
win_min_ver = "6.1";
title = "Prevent the computer from joining a homegroup";
solution = "Set following UI path accordingly:
Computer Configuration/Administrative Templates/Windows Components/HomeGroup/" + title;
test_type = "RegKey";
type = "HKLM";
key = "Software\Policies\Microsoft\Windows\HomeGroup";
item = "DisableHomeGroup";
reg_path = type + "\" + key + "!" + item;
default = script_get_preference("Value");

if(!policy_verify_win_ver(min_ver:win_min_ver)){
  results = policy_report_wrong_os(target_os:target_os);
}else{
  results = policy_match_exact_reg_dword(key:key, item:item, type:type, default:default);
}

value = results["value"];
comment = results["comment"];
compliant = results["compliant"];

policy_reporting(result:value, default:default, compliant:compliant, fixtext:solution,
  type:test_type, test:reg_path, info:comment);
policy_set_kbs(type:test_type, cmd:reg_path, default:default, solution:solution, title:title,
  value:value, compliant:compliant);

exit(0);