Do Not Allow Globally Writable Files

# SPDX-FileCopyrightText: 2025 Greenbone AG
# 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-only

# ------------------------------------------------------------------
# METADATA
# ------------------------------------------------------------------

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.130425");
  script_version("2025-11-21T05:40:28+0000");
  script_tag(name:"last_modification", value:"2025-11-21 05:40:28 +0000 (Fri, 21 Nov 2025)");
  script_tag(name:"creation_date", value:"2025-05-07 11:45:55 +0000 (Wed, 07 May 2025)");
  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("Do Not Allow Globally Writable Files");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2025 Greenbone AG");
  script_family("Policy");
  script_dependencies("compliance_tests.nasl", "compliance_os_check.nasl");

  script_mandatory_keys("Compliance/Launch", "policy/ssh/login/euleros_eulerosvirtual_openeuler_hce");

  script_xref(name:"Policy", value:"EulerOS Baseline: openEuler Security Configuration Baseline (v1.0.0): 1. Initial deployment: 1.1 File Systems: 1.1.6 Do Not Allow Globally Writable Files (Requirement)");
  script_xref(name:"Policy", value:"EulerOS Virtual: openEuler Security Configuration Baseline (v1.0.0): 1. Initial deployment: 1.1 File Systems: 1.1.6 Do Not Allow Globally Writable Files (Requirement)");
  script_xref(name:"Policy", value:"HCE Linux (Huawei Cloud EulerOS): openEuler Security Configuration Baseline (v1.0.0): 1. Initial deployment: 1.1 File Systems: 1.1.6 Do Not Allow Globally Writable Files (Requirement)");
  script_xref(name:"Policy", value:"openEuler Baseline: openEuler Security Configuration Baseline (v1.0.0): 1. Initial deployment: 1.1 File Systems: 1.1.6 Do Not Allow Globally Writable Files (Requirement)");

  script_tag(name:"summary", value:"Globally writable files can be written by any user in the
system, which is generally not needed. If a file is improperly set to globally writable, the file
can be easily tampered with by attackers, causing security risks. Therefore, if a file is required
to be globally writable, the actual scenario must be analyzed for security risks to prevent attacks
via the file.

You can search for globally writable files in the root directory. Note that the /sys and /proc
system directories contain a large number of globally writable files during Linux running. You are
advised to exclude the two directories from the search to avoid confusion.");

  exit(0);
}

include("ssh_func.inc");
include("host_details.inc");
include("policy_reporting_module.inc");

title = "Do Not Allow Globally Writable Files";

solution = "Run the chmod command to remove the globally writable permission if it is not required.

# chmod 755 test
# ll test
-rwxr-xr-x. 1 root root 0 Dec 1 17:34 test";

check_type = "SSH_Cmd";

action = 'Run the command in the terminal:
# find / -xdev -type f -perm -0002 -exec ls -lg {} \\;';

expected_value = 'The output should be empty';

# ------------------------------------------------------------------
# CONNECTION CHECK
# ------------------------------------------------------------------

if(!get_kb_item("login/SSH/success") || !sock = ssh_login_or_reuse_connection()){

  report_ssh_error(title: title,
                   solution: solution,
                   action: action,
                   expected_value: expected_value,
                   check_type: check_type);
  exit(0);
}

# ------------------------------------------------------------------
# CHECK : Verify command ` find / -xdev -type f -perm -0002 -exec ls -lg {} \; `
# ------------------------------------------------------------------

step_cmd = 'find / -xdev -type f -perm -0002 -exec ls -lg {} \\;';
actual_value = ssh_cmd(socket:sock, cmd:step_cmd, return_errors:TRUE, return_linux_errors_only:TRUE);

if(eregmatch(string: actual_value, pattern:"(No such file or directory|Permission denied|Command not found|Segmentation fault|service not found|is not running|syntax error near unexpected token|syntax error: unexpected end of file)", icase: TRUE)){
  compliant = "incomplete";
  comment = "Something went wrong during the audit check. Please try again.";
}else if(!actual_value){
  compliant = "yes";
  comment = "Check passed";
}else{
  compliant = "no";
  comment = "Check failed";
}

# ------------------------------------------------------------------
# REPORT
# ------------------------------------------------------------------

target = get_kb_item("policy/ssh/login/os-release");
comment = "Target: " + target + "\n" + comment;

report_audit(action: action,
             actual_value: actual_value,
             expected_value: expected_value,
             is_compliant: compliant,
             solution: solution,
             check_type: check_type,
             title: title,
             comment: comment);

exit(0);