Security Updates for Microsoft SharePoint Server 2019 (March 2021) - Nessus

High Plugin ID: 147752

This page contains detailed information about the Security Updates for Microsoft SharePoint Server 2019 (March 2021) 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: 147752
Name: Security Updates for Microsoft SharePoint Server 2019 (March 2021)
Filename: smb_nt_ms21_mar_office_sharepoint_2019.nasl
Vulnerability Published: 2021-03-09
This Plugin Published: 2021-03-12
Last Modification Time: 2021-06-03
Plugin Version: 1.6
Plugin Type: local
Plugin Family: Windows : Microsoft Bulletins
Dependencies: microsoft_sharepoint_installed.nbin, ms_bulletin_checks_possible.nasl, smb_hotfixes.nasl
Required KB Items [?]: SMB/MS_Bulletin_Checks/Possible

Vulnerability Information

Severity: High
Vulnerability Published: 2021-03-09
Patch Published: 2021-03-09
CVE [?]: CVE-2021-24104, CVE-2021-27052, CVE-2021-27076
CPE [?]: cpe:/a:microsoft:sharepoint_server

Synopsis

The Microsoft SharePoint Server 2019 installation on the remote host is affected by multiple vulnerabilities.

Description

The Microsoft SharePoint Server 2019 installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

- A session spoofing vulnerability exists. An attacker can exploit this to perform actions with the privileges of another user. (CVE-2021-24104)

- A remote code execution vulnerability. An attacker can exploit this to bypass authentication and execute unauthorized arbitrary commands. (CVE-2021-27076)

- An information disclosure vulnerability. An attacker can exploit this to disclose potentially sensitive information. (CVE-2021-27052)

Solution

Microsoft has released the following security updates to address this issue: -KB4493230 -KB4493231

Public Exploits

Target Network Port(s): 139, 445
Target Asset(s): Host/patch_management_checks
Exploit Available: True (GitHub)
Exploit Ease: Exploits (PoCs) are available

Here's the list of publicly known exploits and PoCs for verifying the Security Updates for Microsoft SharePoint Server 2019 (March 2021) vulnerability:

GitHub: https://github.com/H0j3n/EzpzSharepoint
[CVE-2021-27076]

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 Score Source [?]: CVE-2021-27076
CVSS V2 Vector: AV:N/AC:L/Au:S/C:P/I:P/A:P/E:U/RL:OF/RC:C

CVSS Base Score:	6.5 (Medium)
Impact Subscore:	6.4
Exploitability Subscore:	8.0
CVSS Temporal Score:	4.8 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	4.8 (Medium)

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

CVSS Base Score:	8.8 (High)
Impact Subscore:	5.9
Exploitability Subscore:	2.8
CVSS Temporal Score:	7.7 (High)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	7.7 (High)

STIG Severity [?]: I
STIG Risk Rating: High

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Plugin Source

##
# (C) Tenable Network Security, Inc.
##
# The descriptive text and package checks in this plugin were  
# extracted from the Microsoft Security Updates API. The text
# itself is copyright (C) Microsoft Corporation.
##

include('compat.inc');

if (description)
{
  script_id(147752);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");

  script_cve_id("CVE-2021-24104", "CVE-2021-27052", "CVE-2021-27076");
  script_xref(name:"MSKB", value:"4493230");
  script_xref(name:"MSKB", value:"4493231");
  script_xref(name:"MSFT", value:"MS21-4493230");
  script_xref(name:"MSFT", value:"MS21-4493231");
  script_xref(name:"IAVA", value:"2021-A-0136-S");

  script_name(english:"Security Updates for Microsoft SharePoint Server 2019 (March 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft SharePoint Server 2019 installation on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft SharePoint Server 2019 installation on the
remote host is missing security updates. It is, therefore,
affected by multiple vulnerabilities:

  - A session spoofing vulnerability exists. An attacker can
    exploit this to perform actions with the privileges of
    another user. (CVE-2021-24104)

  - A remote code execution vulnerability. An attacker can
    exploit this to bypass authentication and execute
    unauthorized arbitrary commands. (CVE-2021-27076)

  - An information disclosure vulnerability. An attacker can
    exploit this to disclose potentially sensitive
    information. (CVE-2021-27052)");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/en-us/help/4493230");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/en-us/help/4493231");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:  
  -KB4493230
  -KB4493231");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-27076");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/03/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/03/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:sharepoint_server");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("microsoft_sharepoint_installed.nbin", "smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('smb_func.inc');
include('smb_hotfixes.inc');
include('smb_hotfixes_fcheck.inc');
include('smb_reg_query.inc');
include('install_func.inc');

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

bulletin = 'MS21-03';
app_name = 'Microsoft SharePoint Server';
kbs = make_list(
  '4493230',
  '4493231'
);

if (get_kb_item('Host/patch_management_checks'))
  hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_WARNING);

get_kb_item_or_exit('SMB/Registry/Enumerated', exit_code:1);

# Get path information for Windows.
windir = hotfix_get_systemroot();
if (isnull(windir)) exit(1, 'Failed to determine the location of %windir%.');

paranoid_audit = FALSE;
registry_init();
install = get_single_install(app_name:app_name);
kb_checks =
{
  '2019':
  { '0':
    {'Server':
      [
        {
         'kb'           : '4493230',
         'path'         : install['path'],
         'append'       : 'bin',
         'file'         : 'ascalc.dll',
         'version'      : '16.0.10372.20060',
         'product_name' : 'Microsoft SharePoint Server 2019 Core'
        },
        {#Language File
         'kb'           : '4493231',
         #'path'         : hotfix_get_commonfilesdir(),
         #'append'       : 'microsoft shared\\server16\\server setup controller',
         #'file'         : 'wsssetup.dll',
         #'version'      : '16.0.10372.20060',
         'product_name' : 'Microsoft SharePoint Server 2019 Core'
        }

      ]
    }
  }
};

# Get the specific product / path
param_list = kb_checks[install['Product']][install['SP']][install['Edition']];
# audit if not affected
if(isnull(param_list)) audit(AUDIT_HOST_NOT, 'affected');
port = kb_smb_transport();
reg_keys = get_kb_list('SMB/Registry/HKLM/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/*/DisplayName');
# grab the path otherwise
foreach check (param_list)
{
  if (check['kb'] == '4493231')
  { 
    are_we_vuln = HCF_OLDER;
    foreach display_name (reg_keys)
    {
      if ('KB'+check['kb'] >< display_name)
      {
        are_we_vuln = HCF_OK;
        break;
      }
    }
    if (report_paranoia < 2 && are_we_vuln != HCF_OK)
    {
      paranoid_audit = TRUE;
      are_we_vuln = HCF_OK;
      report = '\n';
      if (check['product_name'])
        report += '  Product : ' + check['product_name'] + '\n';
        report += '  KB : ' + check['kb'] + ' was not confirmed due to Paranoid Check settings \n';
      hotfix_add_report(report, kb:check['kb']);
      break;
    }
  }
  if (!isnull(check['version']))
  {
    path = check['path'];
    if (!empty_or_null(check['append']))
      path = hotfix_append_path(path:check['path'], value:check['append']);
    are_we_vuln = hotfix_check_fversion(
      file:check['file'],
      version:check['version'],
      path:path,
      kb:check['kb'],
      product:check['product_name']
    );
  }
  else
  {
    report = '\n';
    if (check['product_name'])
      report += '  Product : ' + check['product_name'] + '\n';
    if (check['kb'])
      report += '  KB : ' + check['kb'] + '\n';
    hotfix_add_report(report, kb:check['kb']);
  }

  if(are_we_vuln == HCF_OLDER) vuln = TRUE;

}
if (vuln)
{
  port = kb_smb_transport();
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_warning();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  if (paranoid_audit == TRUE) audit(AUDIT_POTENTIAL_VULN, app_name);
  audit(AUDIT_INST_VER_NOT_VULN, app_name);
}

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

Linux / Unix:
/opt/nessus/lib/nessus/plugins/smb_nt_ms21_mar_office_sharepoint_2019.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\smb_nt_ms21_mar_office_sharepoint_2019.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/smb_nt_ms21_mar_office_sharepoint_2019.nasl

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How to Run

Here is how to run the Security Updates for Microsoft SharePoint Server 2019 (March 2021) 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 Windows : Microsoft Bulletins plugin family.
On the right side table select Security Updates for Microsoft SharePoint Server 2019 (March 2021) plugin ID 147752.
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 smb_nt_ms21_mar_office_sharepoint_2019.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a smb_nt_ms21_mar_office_sharepoint_2019.nasl -t <IP/HOST>

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

/opt/nessus/bin/nasl -T - smb_nt_ms21_mar_office_sharepoint_2019.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_nt_ms21_mar_office_sharepoint_2019.nasl -t <IP/HOST>

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References

MSKB | Microsoft Knowledge Base:

4493230, 4493231

MSFT | Microsoft Security Bulletin:

MS21-4493230, MS21-4493231

IAVA | Information Assurance Vulnerability Alert:

2021-A-0136-S

See also:

Similar and related Nessus plugins:

147750 - Security Updates for Microsoft SharePoint Server 2010 (March 2021)
147753 - Security Updates for Microsoft SharePoint Server 2013 (March 2021)
147751 - Security Updates for Microsoft Sharepoint 2016 (March 2021)
147724 - Security Update for Microsoft Visual Studio Code ESLint Extension (March 2021)
147226 - KB5000802: Windows Security Update (March 2021)
147222 - KB5000803: Windows Security Update (March 2021)
147230 - KB5000807: Windows 10 March 2021 Security Update
147220 - KB5000808: Windows 10 Version 1909 March 2021 Security Update
147224 - KB5000809: Windows 10 Version 1803 March 2021 Security Update
147223 - KB5000822: Windows 10 Version 1809 and Windows Server 2019 March 2021 Security Update
147231 - KB5000851: Windows 7 and Windows Server 2008 R2 March 2021 Security Update
147217 - KB5000856: Windows Server 2008 March 2021 Security Update
147221 - KB5000840: Windows Server 2012 March 2021 Security Update
147229 - KB5000853: Windows 8.1 and Windows Server 2012 R2 March 2021 Security Update
147024 - Security Update for Microsoft Exchange Server 2010 SP 3 (March 2021)
147003 - Security Updates for Microsoft Exchange Server (March 2021)
147227 - Microsoft Windows Codecs Library Multiple Vulnerabilities (March 2021)
147228 - Security Updates for Internet Explorer (March 2021)
147749 - Security Updates for Microsoft Visual Studio Products (March 2021)

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file smb_nt_ms21_mar_office_sharepoint_2019.nasl version 1.6. For more plugins, visit the Nessus Plugin Library.

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Security Updates for Microsoft SharePoint Server 2019 (March 2021) - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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