Unpassworded 'guest' Account - Nessus

Critical Plugin ID: 11240

This page contains detailed information about the Unpassworded 'guest' Account 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: 11240
Name: Unpassworded 'guest' Account
Filename: account_guest.nasl
Vulnerability Published: 2001-01-01
This Plugin Published: 2003-02-20
Last Modification Time: 2022-04-11
Plugin Version: 1.35
Plugin Type: remote
Plugin Family: Default Unix Accounts
Dependencies: account_check.nasl, find_service1.nasl, ssh_detect.nasl
Excluded KB Items [?]: global_settings/supplied_logins_only

Vulnerability Information

Severity: Critical
Vulnerability Published: 2001-01-01
Patch Published: N/A
CVE [?]: CVE-1999-0502
CPE [?]: N/A
Default Account Vulnerability: True

Synopsis

The remote host has an account with a blank password.

Description

The account 'guest' has no password set. An attacker may use it to gain further privileges on this system.

Solution

Set a password for this account or disable it.

Public Exploits

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

Here's the list of publicly known exploits and PoCs for verifying the Unpassworded 'guest' Account vulnerability:

Metasploit: exploit/multi/ssh/sshexec
[SSH User Code Execution]
Metasploit: auxiliary/scanner/telnet/brocade_enable_login
[Brocade Enable Login Check Scanner]
Metasploit: auxiliary/scanner/db2/db2_auth
[DB2 Authentication Brute Force Utility]
Metasploit: auxiliary/scanner/http/dell_idrac
[Dell iDRAC Default Login]
Metasploit: auxiliary/scanner/http/dlink_dir_300_615_http_login
[D-Link DIR-300A / DIR-320 / DIR-615D HTTP Login Utility]
Metasploit: auxiliary/scanner/http/dlink_dir_615h_http_login
[D-Link DIR-615H HTTP Login Utility]
Metasploit: auxiliary/scanner/http/dlink_dir_session_cgi_http_login
[D-Link DIR-300B / DIR-600B / DIR-815 / DIR-645 HTTP Login Utility]
Metasploit: auxiliary/scanner/ftp/ftp_login
[FTP Authentication Scanner]
Metasploit: auxiliary/scanner/http/http_login
[HTTP Login Utility]
Metasploit: auxiliary/scanner/http/joomla_bruteforce_login
[Joomla Bruteforce Login Utility]
Metasploit: auxiliary/scanner/mysql/mysql_login
[MySQL Login Utility]
Metasploit: auxiliary/scanner/nntp/nntp_login
[NNTP Login Utility]
Metasploit: auxiliary/scanner/oracle/oracle_login
[Oracle RDBMS Login Utility]
Metasploit: auxiliary/scanner/pcanywhere/pcanywhere_login
[PcAnywhere Login Scanner]
Metasploit: auxiliary/scanner/postgres/postgres_login
[PostgreSQL Login Utility]
Metasploit: auxiliary/scanner/rservices/rexec_login
[rexec Authentication Scanner]
Metasploit: auxiliary/scanner/rservices/rlogin_login
[rlogin Authentication Scanner]
Metasploit: auxiliary/scanner/rservices/rsh_login
[rsh Authentication Scanner]
Metasploit: auxiliary/scanner/ssh/ssh_login
[SSH Login Check Scanner]
Metasploit: auxiliary/scanner/telnet/telnet_login
[Telnet Login Check Scanner]
Metasploit: auxiliary/scanner/http/tomcat_mgr_login
[Tomcat Application Manager Login Utility]
Metasploit: auxiliary/scanner/vmware/vmauthd_login
[VMWare Authentication Daemon Login Scanner]
Metasploit: auxiliary/scanner/vmware/vmware_http_login
[VMWare Web Login Scanner]
Metasploit: auxiliary/scanner/winrm/winrm_login
[WinRM Login Utility]
Metasploit: auxiliary/scanner/http/wordpress_xmlrpc_login
[Wordpress XML-RPC Username/Password Login Scanner]
Exploit-DB: exploits/linux/remote/35581.rb
[EDB-35581: Varnish Cache CLI Interface - Remote Code Execution (Metasploit)]
Exploit-DB: exploits/multiple/remote/41694.rb
[EDB-41694: SSH - User Code Execution (Metasploit)]

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:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:TF/RC:C

CVSS Base Score:	7.5 (High)
Impact Subscore:	6.4
Exploitability Subscore:	10.0
CVSS Temporal Score:	6.1 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.1 (Medium)

CVSS V3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:T/RC:C

CVSS Base Score:	9.8 (Critical)
Impact Subscore:	5.9
Exploitability Subscore:	3.9
CVSS Temporal Score:	8.9 (High)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	8.9 (High)

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Plugin Source

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

account = "guest";

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(11240);
  script_version("1.35");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");

  script_cve_id("CVE-1999-0502");
  script_bugtraq_id(30);

  script_name(english:"Unpassworded 'guest' Account");

  script_set_attribute(attribute:"synopsis", value:
"The remote host has an account with a blank password.");
  script_set_attribute(attribute:"description", value:
"The account 'guest' has no password set. 
An attacker may use it to gain further privileges on this system.");
  script_set_attribute(attribute:"solution", value:
"Set a password for this account or disable it.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:TF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:T/RC:C");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'SSH User Code Execution');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2001/01/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2003/02/20");

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

  script_category(ACT_GATHER_INFO);
  script_family(english:"Default Unix Accounts");

  script_copyright(english:"This script is Copyright (C) 2003-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

#
# The script code starts here : 
#
include("audit.inc");
include("default_account.inc");
include("global_settings.inc");

if (supplied_logins_only) audit(AUDIT_SUPPLIED_LOGINS_ONLY);

if (! thorough_tests && ! get_kb_item("Settings/test_all_accounts"))
 exit(0, "Neither thorough_tests nor 'Settings/test_all_accounts' is set.");

affected = FALSE;
ssh_ports = get_service_port_list(svc: "ssh", default:22);
foreach port (ssh_ports)
{
  port = check_account(login:account, port:port, svc:"ssh");
  if (port)
  {
    affected = TRUE;
    security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
  }
}
if(affected) exit(0);

telnet_ports = get_service_port_list(svc: "telnet", default:23);
foreach port (telnet_ports)
{
  port = check_account(login:account, port:port, svc:"telnet");
  if (port)
  {
    affected = TRUE;
    security_report_v4(port:port, severity:SECURITY_HOLE, extra:default_account_report());
  }
}
if(!affected) audit(AUDIT_HOST_NOT, "affected");

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

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

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How to Run

Here is how to run the Unpassworded 'guest' Account 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 Default Unix Accounts plugin family.
On the right side table select Unpassworded 'guest' Account plugin ID 11240.
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 account_guest.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

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

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

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

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References

BID | SecurityFocus Bugtraq ID:

See also:

Similar and related Nessus plugins:

11243 - Unpassworded '4Dgifts' Account
11250 - Unpassworded 'backdoor' Account
11248 - Unpassworded 'date' Account
11242 - Unpassworded 'demos' Account
11241 - Unpassworded 'EZsetup' Account
11254 - Unpassworded 'friday' Account
11253 - Unpassworded 'hax0r' Account
17575 - Unpassworded 'help' Account
11249 - Unpassworded 'jack' Account
11266 - Unpassworded 'jill' Account
11246 - Unpassworded 'lp' Account
18527 - Unpassworded 'mpi' Account
11244 - Unpassworded 'OutOfBox' Account
34083 - Unpassworded 'r00t' account
11245 - Unpassworded 'root' Account
11259 - Unpassworded 'StoogR' Account
11247 - Unpassworded 'sync' Account
11252 - Unpassworded 'toor' Account
11251 - Unpassworded 'tutor' Account
15583 - Unpassworded 'bash' Backdoor Account
10778 - SiteScope Web Service Unpassworded Access
10483 - PostgreSQL Default Unpassworded Account

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file account_guest.nasl version 1.35. For more plugins, visit the Nessus Plugin Library.

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Unpassworded 'guest' Account - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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