Ensure Kernel SMEP is Enabled

# 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("1.3.6.1.4.1.25623.1.0.130332");
  script_version("2026-01-14T05:47:41+0000");
  script_tag(name:"last_modification", value:"2026-01-14 05:47:41 +0000 (Wed, 14 Jan 2026)");
  script_tag(name:"creation_date", value:"2025-05-07 11:44:20 +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("Ensure Kernel SMEP is Enabled");

  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");

  script_xref(name:"Policy", value:"EulerOS Baseline: openEuler Security Configuration Baseline (v1.0.0): 3. Running and Services: 3.5 Kernel: 3.5.5 Ensure Kernel SMEP is Enabled (Requirement)");
  script_xref(name:"Policy", value:"EulerOS Virtual: openEuler Security Configuration Baseline (v1.0.0): 3. Running and Services: 3.5 Kernel: 3.5.5 Ensure Kernel SMEP is Enabled (Requirement)");
  script_xref(name:"Policy", value:"openEuler Baseline: openEuler Security Configuration Baseline (v1.0.0): 3. Running and Services: 3.5 Kernel: 3.5.5 Ensure Kernel SMEP is Enabled (Requirement)");

  script_tag(name:"summary", value:"Supervisor Mode Execution Prevention (SMEP) can be enabled to
prevent the user-space code execution on the kernel. If SMEP is not enabled, attackers can execute
the user-space code through kernel-mode code redirection, which increases the attack surface and
reduces system security.

SMEP is enabled by default in openEuler.");

  exit(0);
}

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

title = "Ensure Kernel SMEP is Enabled";

solution = "If SMEP is disabled, delete nosmep from the boot parameters in the grub.cfg file.

# vim /boot/efi/EFI/openEuler/grub.cfg";

check_type = "SSH_Cmd";

action = '1. The output should contain "smep"
2. The output should be empty.';

expected_value = 'The output should not 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);
}

overall_pass = FALSE;
actual_value = "";

# ------------------------------------------------------------------
# CHECK 1 :  Verify command cat /proc/cpuinfo | grep "smep"
# ------------------------------------------------------------------
step_cmd_check_1 = 'cat /proc/cpuinfo | grep "smep"';
step_res_check_1 = ssh_cmd(socket:sock, cmd:step_cmd_check_1, return_errors:TRUE, return_linux_errors_only:TRUE);
actual_value += '1. ' + step_res_check_1 + '\n';
check_result_1 = FALSE;
if(step_res_check_1){
  check_result_1 = TRUE;
}

# ------------------------------------------------------------------
# CHECK 2 :  Verify command cat /proc/cmdline | grep -i "nosmep"
# ------------------------------------------------------------------
step_cmd_check_2 = 'cat /proc/cmdline | grep -i "nosmep"';
step_res_check_2 = ssh_cmd(socket:sock, cmd:step_cmd_check_2, return_errors:TRUE, return_linux_errors_only:TRUE);
actual_value += '2. ' + step_res_check_2 + '\n';
check_result_2 = FALSE;
if(!step_res_check_2){
  check_result_2 = TRUE;
}

# ------------------------------------------------------------------
# FINAL RESULT
# ------------------------------------------------------------------

if(!step_res_check_1){
  actual_value = "Not applicable";
}

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|Not applicable)", icase: TRUE)){
  compliant = "incomplete";
  comment = "Something went wrong during the some audit check. Please try again.";
}
else if(check_result_1 && check_result_2){
  compliant = "yes";
  comment = "All checks passed";
}else{
  compliant = "no";
  comment = "One or more checks 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);