Cisco IOS Compliance Check

# SPDX-FileCopyrightText: 2017 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

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.106431");
  script_version("2026-02-02T05:59:28+0000");
  script_tag(name:"last_modification", value:"2026-02-02 05:59:28 +0000 (Mon, 02 Feb 2026)");
  script_tag(name:"creation_date", value:"2017-01-11 10:55:08 +0700 (Wed, 11 Jan 2017)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");

  script_tag(name:"qod", value:"98");

  script_name("Cisco IOS Compliance Check");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("Policy");
  script_dependencies("gb_cisco_ios_consolidation.nasl");
  script_mandatory_keys("cisco/ios/ssh-login/detected");

  script_tag(name:"summary", value:"Runs the Cisco IOS Compliance Check with the provided policy
  file and stores the results in the kb.");

  script_add_preference(name:"Cisco IOS Policies", type:"file", value:"", id:1);
  script_add_preference(name:"Enable Password", type:"password", value:"", id:2);

  exit(0);
}

include("ssh_func.inc");

if (!get_kb_item("cisco/ios/ssh-login/detected"))
  exit(0);

# nb: Check the rules/sections for a certain pattern in the config
function check_rule(config, pattern, section, present) {
  # nb: Check for section
  if (section) {
    ok = FALSE;
    for (i=0; i < max_index(config); i++) {
      sec = eregmatch(pattern: section, string: config[i]);
      if (!isnull(sec)) {
        j = 1;
        sec_ok = FALSE;
        while (ereg(pattern: "^ ", string: config[i+j])) {
          match = eregmatch(pattern: pattern, string: config[i+j]);
          if ((!isnull(match) && present == "true") || (isnull(match) && present == "false")) {
            sec_ok = TRUE;
          }
          j++;
        }
        if (sec_ok)
          ok = TRUE;
        else
          ok = FALSE;
        i = i+j-1;
      }
    }
    return ok;
  }

  # nb: Check without section
  foreach line (config) {
    match = eregmatch(pattern: pattern, string: line);
    if ((!isnull(match) && present == "true") || (isnull(match) && present == "false")) {
      return TRUE;
    }
  }

  return FALSE;
}


policy_file = script_get_preference_file_content("Cisco IOS Policies");
if (!policy_file)
  exit(0);

policy_lines = split(policy_file, keep: FALSE);

max = max_index(policy_lines);
if (max < 5) {
  set_kb_item(name: "policy/cisco_ios_compliance/error",
              value: "The Cisco IOS policy is empty. No check can be done.\n");
  exit(0);
}

sock = ssh_login_or_reuse_connection();
if (!sock)
  exit(0);

enable_password = script_get_preference("Enable Password");

if (!isnull(enable_password)) {
  sess = ssh_session_id_from_sock(sock);

  if (!sess) {
    close(sock);
    exit(0);
  }

  shell = ssh_shell_open( sess );

  if (!shell) {
    close(sock);
    exit(0);
  }

  ssh_shell_write(shell, cmd: 'enable\n');

  buf = ssh_read_from_shell(sess: shell, pattern: "Password:");

  if (!buf || "Password:" >!< buf) {
    close(sock);
    exit(0);
  }

  ssh_shell_write(shell, cmd: enable_password + '\n');

  buf = ssh_read_from_shell(sess: shell, pattern:"#");

  if (!buf || "#" >!< buf) {
    close(sock);
    exit(0);
  }

  ssh_shell_write(shell, cmd: 'terminal length 0\n');
  ssh_shell_write(shell, cmd: 'show running-config\n');

  config = ssh_read_from_shell(sess: shell, pattern: "^end$", timeout:30, retry:10);
}
else {
  config = ssh_cmd(socket: sock, cmd: 'show running-config\n', nosh: TRUE);
}

if (sock)
  close(sock);

# strip the comments and split every line
config = ereg_replace(pattern: "!..", string: config, replace: "");
config = split(config, keep: FALSE);

if (max_index(config) < 5) {
  set_kb_item(name: "policy/cisco_ios_compliance/error",
              value: "The retrieved IOS configuration seems to be to small (< 5 lines). Check if the login
account has enough privilege to run 'show running-config'. No checks will be done.\n");
  exit(0);
}

for (r=0; r<max; r++) {
  if (policy_lines[r] == "")
    continue;

  entry = split(policy_lines[r], sep: ":", keep: FALSE);
  if (entry[0] == "title")
    title = entry[1];
  else if (entry[0] == "desc")
    desc = entry[1];
  else if (entry[0] == "solution")
    solution = entry[1];
  else if (entry[0] == "fix")
    fix = entry[1];
  else if (entry[0] == "section")
    section = entry[1];
  else if (entry[0] == "pattern")
    pattern = entry[1];
  else if (entry[0] == "present")
    present = entry[1];

  if ((r == max-1) || (policy_lines[r+1] == "")) {
    if (check_rule(config: config, section: section, pattern: pattern, present: present))
      comp_pass += title + '||' + desc + '||' + pattern + '||' + present + '\n';
    else {
      comp_fail += title + '||' + desc + '||' + solution;
      if (fix && fix != "")
        comp_fail += '||' + fix;
      comp_fail += '\n';
    }

    section = "";
    fix = "";
  }
}

if (comp_pass)
  set_kb_item(name: "policy/cisco_ios_compliance/passed", value: comp_pass);
if (comp_fail)
  set_kb_item(name: "policy/cisco_ios_compliance/failed", value: comp_fail);

exit(0);