Do Not Start the debug-shell Service

# 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("1.3.6.1.4.1.25623.1.0.130472");
  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:"2025-09-25 11:58:32 +0000 (Thu, 25 Sep 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 Start the debug-shell Service");

  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/eulerosvirtual");

  script_xref(name:"Policy", value:"EulerOS Virtual: EulerOS Virtual Linux Security Configuration (v1.0.0): 1. Initial deployment: 1.2 Software: 1.2.6 Do Not Start the debug-shell Service (Requirement)");

  script_tag(name:"summary", value:"The debug-shell service is used to locate faults that occur
during system boot. This service is installed with systemd. The debug-shell service requires no
authentication, that is, attackers can access the root shell by simply pressing Ctrl+Alt+F9 during
systemd startup when the OS is booting. This makes the OS boot process highly risky, because it
allows attackers to tamper with data and execute unauthorized programs to damage the system.

By default, the debug-shell service is disabled in openEuler.");

  exit(0);
}

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

title = "Do Not Start the debug-shell Service";

solution = "Disable the debug-shell service on a server where the debug-shell component has been
installed.

# systemctl --now disable debug-shell";

check_type = "SSH_Cmd";

action = 'Run the command in the terminal:
# systemctl is-enabled debug-shell';

expected_value = 'The output should be equal to "disabled" or be equal to "not-found" or contain "Failed to get unit file state"';

# ------------------------------------------------------------------
# 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 : Check if  debug-shell  service is enabled or installed
# ------------------------------------------------------------------

step_cmd = 'systemctl is-enabled debug-shell';
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 == 'disabled' || actual_value == 'not-found' || strstr(actual_value, 'Failed to get unit file state')){
  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);