Security Updates for Microsoft Exchange Server (February 2021) - Nessus

Medium Plugin ID: 146343

This page contains detailed information about the Security Updates for Microsoft Exchange Server (February 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: 146343
Name: Security Updates for Microsoft Exchange Server (February 2021)
Filename: smb_nt_ms21_feb_exchange.nasl
Vulnerability Published: 2021-02-09
This Plugin Published: 2021-02-09
Last Modification Time: 2022-04-04
Plugin Version: 1.8
Plugin Type: local
Plugin Family: Windows : Microsoft Bulletins
Dependencies: microsoft_exchange_installed.nbin, ms_bulletin_checks_possible.nasl
Required KB Items [?]: SMB/MS_Bulletin_Checks/Possible

Vulnerability Information

Severity: Medium
Vulnerability Published: 2021-02-09
Patch Published: 2021-02-09
CVE [?]: CVE-2021-24085
CPE [?]: cpe:/a:microsoft:exchange_server

Synopsis

The Microsoft Exchange Server installed on the remote host is affected by a spoofing vulnerability.

Description

The Microsoft Exchange Server installed on the remote host is missing security updates. It is, therefore, affected by a spoofing vulnerability:

- A spoofing vulnerability exists. An attacker can exploit this to perform actions with the privileges of another user. (CVE-2021-24085)

Solution

Microsoft has released the following security updates to address this issue: -KB4602269

Public Exploits

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

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

GitHub: https://github.com/sourceincite/CVE-2021-24085
[CVE-2021-24085]

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-2021-24085
CVSS V2 Vector: AV:N/AC:M/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C

CVSS Base Score:	6.0 (Medium)
Impact Subscore:	6.4
Exploitability Subscore:	6.8
CVSS Temporal Score:	4.7 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	4.7 (Medium)

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

CVSS Base Score:	5.5 (Medium)
Impact Subscore:	3.4
Exploitability Subscore:	2.1
CVSS Temporal Score:	5.0 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	5.0 (Medium)

STIG Severity [?]: II
STIG Risk Rating: Medium

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Plugin Source

#%NASL_MIN_LEVEL 70300
#
# (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('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(146343);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/04");

  script_cve_id("CVE-2021-24085");
  script_xref(name:"MSKB", value:"4602269");
  script_xref(name:"MSFT", value:"MS21-4602269");
  script_xref(name:"IAVA", value:"2021-A-0069-S");

  script_name(english:"Security Updates for Microsoft Exchange Server (February 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft Exchange Server installed on the remote host is affected by a spoofing vulnerability.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Exchange Server installed on the remote host
is missing security updates. It is, therefore, affected by
a spoofing vulnerability:

- A spoofing vulnerability exists. An attacker can
exploit this to perform actions with the privileges of
another user. (CVE-2021-24085)");
  # https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-microsoft-exchange-server-2019-and-2016-february-9-2021-kb4602269-2f3c3a74-094b-6669-2ea0-025101d11f1a
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3d7c1580");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:
 -KB4602269");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-24085");

  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:"2021/02/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/02/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/02/09");

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

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

  script_copyright(english:"This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('vcf_extras_microsoft.inc');

var app_info = vcf::microsoft::exchange::get_app_info();

var constraints =
[
  {
    'product' : '2016',
    'unsupported_cu' : 17,
    'cu' : 18,
    'min_version': '15.01.2106.0',
    'fixed_version': '15.01.2106.8'
  },
  {
    'product': '2016',
    'unsupported_cu': 17,
    'cu' : 19,
    'min_version': '15.01.2176.0',
    'fixed_version': '15.01.2176.4'
  },
  {
    'product' : '2019',
    'unsupported_cu' : 6,
    'cu' : 7,
    'min_version': '15.02.721.0',
    'fixed_version': '15.02.721.8'
  },
  {
    'product' : '2019',
    'unsupported_cu' : 6,
    'cu' : 8,
    'min_version': '15.02.792.0',
    'fixed_version': '15.02.792.5'
  }
];

vcf::microsoft::exchange::check_version_and_report
(
  app_info:app_info,
  bulletin:'MS21-02',
  constraints:constraints,
  severity:SECURITY_WARNING
);

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_feb_exchange.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\smb_nt_ms21_feb_exchange.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/smb_nt_ms21_feb_exchange.nasl

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How to Run

Here is how to run the Security Updates for Microsoft Exchange Server (February 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 Exchange Server (February 2021) plugin ID 146343.
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_feb_exchange.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a smb_nt_ms21_feb_exchange.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_feb_exchange.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_feb_exchange.nasl -t <IP/HOST>

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References

MSKB | Microsoft Knowledge Base:

4602269

MSFT | Microsoft Security Bulletin:

MS21-4602269

IAVA | Information Assurance Vulnerability Alert:

2021-A-0069-S

See also:

Similar and related Nessus plugins:

147558 - FreeBSD : Node.js -- February 2021 Security Releases (2f3cd69e-7dee-11eb-b92e-0022489ad614)
146326 - KB4601315: Windows 10 Version 1909 February 2021 Security Update
146329 - KB4601318: Windows 10 Version 1607 and Windows Server 2016 February 2021 Security Update
146335 - KB4601331: Windows 10 February 2021 Security Update
146337 - KB4601345: Windows 10 Version 1809 and Windows Server 2019 February 2021 Security Update
146342 - KB4601363: Windows 7 and Windows Server 2008 R2 February 2021 Security Update
146338 - KB4601357: Windows Server 2012 February 2021 Security Update
146339 - KB4601354: Windows 10 Version 1803 February 2021 Security Update
146327 - KB4601366: Windows Server 2008 February 2021 Security Update
146341 - KB4601349: Windows 8.1 and Windows Server 2012 R2 February 2021 Security Update
146332 - Security Update for Forefront Endpoint Protection (February 2021)
146334 - Security Update for Windows Defender (February 2021)

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file smb_nt_ms21_feb_exchange.nasl version 1.8. For more plugins, visit the Nessus Plugin Library.

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Security Updates for Microsoft Exchange Server (February 2021) - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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