Microsoft Windows SMB Guest Account Local User Access - Nessus

High   Plugin ID: 26919

This page contains detailed information about the Microsoft Windows SMB Guest Account Local User Access 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

ID: 26919
Name: Microsoft Windows SMB Guest Account Local User Access
Filename: smb_guest_account.nasl
Vulnerability Published: 1999-01-01
This Plugin Published: 2007-10-04
Last Modification Time: 2020-09-21
Plugin Version: 1.19
Plugin Type: remote
Plugin Family: Windows
Dependencies: smb_login.nasl
Required KB Items [?]: SMB/guest_enabled

Vulnerability Information

Severity: High
Vulnerability Published: 1999-01-01
Patch Published: N/A
CVE [?]: CVE-1999-0505
CPE [?]: cpe:/o:microsoft:windows

Synopsis

It is possible to log into the remote host.

Description

The remote host is running one of the Microsoft Windows operating systems or the SAMBA daemon. It was possible to log into it as a guest user using a random account.

Solution

In the group policy change the setting for 'Network access: Sharing and security model for local accounts' from 'Guest only - local users authenticate as Guest' to 'Classic - local users authenticate as themselves'. Disable the Guest account if applicable.

If the SAMBA daemon is running, double-check the SAMBA configuration around guest user access and disable guest access if appropriate

Public Exploits

Target Network Port(s): N/A
Target Asset(s): N/A
Exploit Available: True (Metasploit Framework)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the Microsoft Windows SMB Guest Account Local User Access vulnerability:

  1. Metasploit: exploit/windows/smb/psexec
    [Microsoft Windows Authenticated Powershell Command Execution]

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.

Risk Information

CVSS Score Source [?]: CVE-1999-0505
CVSS Score Rationale: AV:N is justified since the plugin tries to login via network services. NIST specifies that the vulnerability pertains to a domain user. Given that the plugin only tests for a guest account, which likely has limited permissions, the CIA is partial instead of complete.
CVSS V2 Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
CVSS Base Score:7.5 (High)
Impact Subscore:6.4
Exploitability Subscore:10.0
CVSS Temporal Score:NA (None)
CVSS Environmental Score:NA (None)
Modified Impact Subscore:NA
Overall CVSS Score:7.5 (High)

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Plugin Source

This is the smb_guest_account.nasl nessus plugin source code. This script is Copyright (C) 2007-2020 and is owned by Tenable, Inc. or an Affiliate thereof. 

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

include('compat.inc');

if (description)
{
 script_id(26919);
 script_version("1.19");
 script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/21");

 script_cve_id("CVE-1999-0505");

 script_name(english:"Microsoft Windows SMB Guest Account Local User Access");
 script_summary(english:"Attempts to log into the remote host");

 script_set_attribute(attribute:"synopsis", value:"It is possible to log into the remote host.");
 script_set_attribute(attribute:"description", value:
"The remote host is running one of the Microsoft Windows operating
systems or the SAMBA daemon. It was possible to log into it as a guest
user using a random account.");
 script_set_attribute(attribute:"solution", value:
"In the group policy change the setting for 'Network access: Sharing
and security model for local accounts' from 'Guest only - local users
authenticate as Guest' to 'Classic - local users authenticate as
themselves'. Disable the Guest account if applicable.

If the SAMBA daemon is running, double-check the SAMBA configuration
around guest user access and disable guest access if appropriate");
 script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
 script_set_attribute(attribute:"cvss_score_source", value:"CVE-1999-0505");
 script_set_attribute(attribute:"cvss_score_rationale", value:"AV:N is justified since the plugin tries to login via network services. NIST specifies that the vulnerability pertains to a domain user. Given that the plugin only tests for a guest account, which likely has limited permissions, the CIA is partial instead of complete.");
 script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows");
 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:'Microsoft Windows Authenticated Powershell Command Execution');
 script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"1999/01/01");
 script_set_attribute(attribute:"plugin_publication_date", value:"2007/10/04");

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

 script_category(ACT_GATHER_INFO);
 script_copyright(english:"This script is Copyright (C) 2007-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
 script_family(english:"Windows");

 script_dependencies("smb_login.nasl");
 script_require_keys("SMB/guest_enabled");
 exit(0);
}

#

include('smb_func.inc');

val = get_kb_item("SMB/guest_enabled");

if (val)
  security_hole(kb_smb_transport());

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

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

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How to Run

Here is how to run the Microsoft Windows SMB Guest Account Local User Access as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

  1. Click to start a New Scan.
  2. Select Advanced Scan.
  3. Navigate to the Plugins tab.
  4. On the top right corner click to Disable All plugins.
  5. On the left side table select Windows plugin family.
  6. On the right side table select Microsoft Windows SMB Guest Account Local User Access plugin ID 26919.
  7. Specify the target on the Settings tab and click to Save the scan.
  8. 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 smb_guest_account.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

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

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

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

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References

See also: Similar and related Nessus plugins:
  • 26918 - Microsoft Windows SMB Blank Administrator Password
  • 147227 - Microsoft Windows Codecs Library Multiple Vulnerabilities (March 2021)
  • 149388 - Microsoft Windows Web Media Extensions Library RCE (May 2021)
  • 152100 - Windows SeriousSAM HiveNightmare Registry Read Vulnerability
  • 152428 - Security Update for Microsoft Azure Active Directory Connect (August 2021)
  • 153214 - Security Updates for Microsoft Internet Explorer OOB (Sept 2021) (deprecated)
  • 155962 - Security Updates for Exchange (November 2021) (Remote)
  • 157879 - Security Update for .NET Core (February 2022)
  • 18028 - MS05-019: Vulnerabilities in TCP/IP Could Allow Remote Code Execution (893066) (uncredentialed check)
  • 19407 - MS05-043: Vulnerability in Printer Spooler Service Could Allow Remote Code Execution (896423) (uncredentialed check)
  • 19408 - MS05-039: Vulnerability in Plug and Play Service Could Allow Remote Code Execution (899588) (uncredentialed check)
  • 20006 - MS05-046: Vulnerability in the Client Service for NetWare Could Allow Remote Code Execution (899589) (uncredentialed check)
  • 21193 - MS05-047: Plug and Play Remote Code Execution and Local Privilege Elevation (905749) (uncredentialed check)
  • 21334 - MS06-018: Vulnerability in Microsoft Distributed Transaction Coordinator Could Allow DoS (913580) (uncredentialed check)
  • 21696 - MS06-025: Vulnerability in Routing and Remote Access Could Allow Remote Code Execution (911280) (uncredentialed check)
  • 22034 - MS06-035: Vulnerability in Server Service Could Allow Remote Code Execution (917159) (uncredentialed check)
  • 22194 - MS06-040: Vulnerability in Server Service Could Allow Remote Code Execution (921883) (uncredentialed check)
  • 26918 - Microsoft Windows SMB Blank Administrator Password
  • 34412 - MS08-059: Microsoft Host Integration Server (HIS) SNA RPC Request Remote Overflow (956695) (uncredentialed check)
  • 34477 - MS08-067: Microsoft Windows Server Service Crafted RPC Request Handling Remote Code Execution (958644) (ECLIPSEDWING) (uncredentialed check)
  • 34821 - MS08-067: Vulnerability in Server Service Could Allow Remote Code Execution (958644) (ECLIPSEDWING) (uncredentialed check / IPS)
  • 35362 - MS09-001: Microsoft Windows SMB Vulnerabilities Remote Code Execution (958687) (uncredentialed check)
  • 35634 - MS KB960715: Cumulative Security Update of ActiveX Kill Bits
  • 35635 - MS09-004: Vulnerability in Microsoft SQL Server Could Allow Remote Code Execution (959420) (uncredentialed check)
  • 46017 - MS10-025: Vulnerability in Microsoft Windows Media Services Could Allow Remote Code Execution (980858) (uncredentialed check)
  • 47045 - MS KB2219475: Windows Help Center hcp:// Protocol Handler Arbitrary Code Execution
  • 47556 - MS10-012: Vulnerabilities in SMB Could Allow Remote Code Execution (971468) (uncredentialed check)
  • 47750 - MS KB2286198: Windows Shell Shortcut Icon Parsing Arbitrary Code Execution (EASYHOOKUP)
  • 48405 - MS10-054: Vulnerabilities in SMB Server Could Allow Remote Code Execution (982214) (remote check)
  • 49274 - MS KB2401593: Microsoft Outlook Web Access (OWA) CSRF
  • 51587 - MS KB2488013: Internet Explorer CSS Import Rule Processing Arbitrary Code Execution
  • 53503 - MS11-020: Vulnerability in SMB Server Could Allow Remote Code Execution (2508429) (remote check)
  • 55286 - MS11-048: Vulnerability in SMB Server Could Allow Denial of Service (2536275) (remote check)
  • 62224 - MS KB2755399: Update for Vulnerabilities in Adobe Flash Player in Internet Explorer 10
  • 63155 - Microsoft Windows Unquoted Service Path Enumeration

Version

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

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