Linux: Local world-writeable files

# Copyright (C) 2019 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("1.3.6.1.4.1.25623.1.0.109818");
  script_version("2021-05-18T12:49:08+0000");
  script_tag(name:"last_modification", value:"2021-05-18 12:49:08 +0000 (Tue, 18 May 2021)");
  script_tag(name:"creation_date", value:"2019-03-18 11:05:45 +0100 (Mon, 18 Mar 2019)");
  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("Linux: Local world-writeable files");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2019 Greenbone Networks GmbH");
  script_family("Policy");
  script_dependencies("gather-package-list.nasl", "compliance_tests.nasl");
  script_mandatory_keys("Compliance/Launch");
  script_exclude_keys("ssh/no_linux_shell");

  script_xref(name:"Policy", value:"CIS Distribution Independent Linux v2.0.0: 6.1.10 Ensure no world writable files exist (Scored)");
  script_xref(name:"Policy", value:"CIS CentOS Linux 8 Benchmark v1.0.0: 6.1.10 Ensure no world writable files exist (Scored)");
  script_xref(name:"Policy", value:"CIS Controls Version 7: 5.1 Establish Secure Configurations");
  script_xref(name:"Policy", value:"CIS Controls Version 7: 13 Data Protection");

  script_tag(name:"summary", value:"Anyone is allowed to modify world-writeable files. This makes
these files to a security risk.

This script checks if any world-writeable files exist locally on the host.

Note: This script dramatically increases the scan duration.");

  exit(0);
}

include("ssh_func.inc");
include("policy_functions.inc");

cmd = "df --local --output='target' | xargs -I '{}' find '{}' -xdev -type f -perm -0002";
title = "Local world-writeable files";
solution = "Run 'chmod o-w FILE' to deny write access for others";
test_type = "SSH_Cmd";
default = "None";
comment = "";
value = "None";

if(!get_kb_item("login/SSH/success") || !sock = ssh_login_or_reuse_connection()){
  value = "Error";
  compliant = "incomplete";
  comment = "No SSH connection";
}else{
  compliant = "yes";
  ssh_cmd = 'df --local --output="target" | grep \'/\' | xargs -I \'{}\' find \'{}\' -xdev -type f -perm -0002 2>/dev/null';
  files = ssh_cmd(cmd:ssh_cmd, socket:sock, return_errors:FALSE);
  if(files){
    compliant = "no";
    files_list = split(files, keep:FALSE);
    value = policy_build_string_from_list(list:files_list, sep:",");
  }
}

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

exit(0);