Security Update for Microsoft Azure Active Directory Connect (August 2021) - Nessus

High Plugin ID: 152428

This page contains detailed information about the Security Update for Microsoft Azure Active Directory Connect (August 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: 152428
Name: Security Update for Microsoft Azure Active Directory Connect (August 2021)
Filename: smb_nt_ms21_aug_azure_ad_connect.nasl
Vulnerability Published: 2021-08-10
This Plugin Published: 2021-08-10
Last Modification Time: 2021-09-22
Plugin Version: 1.4
Plugin Type: local
Plugin Family: Windows
Dependencies: microsoft_azure_ad_connect_installed.nbin
Required KB Items [?]: installed_sw/Microsoft Azure AD Connect

Vulnerability Information

Severity: High
Vulnerability Published: 2021-08-10
Patch Published: 2021-08-10
CVE [?]: CVE-2021-36949
CPE [?]: x-cpe:/a:microsoft:azure_active_directory_connect

Synopsis

The remote host has an application installed that is missing a security update.

Description

An authentication bypass exists in Microsoft Azure Active Directory Connect. An attacker with domain user credentials may perform a man-in-the-middle between a domain controller and the Azure AD Connect server to exploit this vulnerability.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade Azure Active Directory Connect to version 1.6.11.3, 2.0.8.0 or later.

Public Exploits

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

Here's the list of publicly known exploits and PoCs for verifying the Security Update for Microsoft Azure Active Directory Connect (August 2021) vulnerability:

GitHub: https://github.com/r0eXpeR/supplier
[CVE-2021-36949]
GitHub: https://github.com/Maxwitat/Check-AAD-Connect-for-CVE-2021-36949-vulnerability
[CVE-2021-36949: check if Azure AD Connect is affected by the vulnerability described in ...]

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-2021-36949
CVSS V2 Vector: AV:A/AC:M/Au:S/C:P/I:P/A:P/E:U/RL:OF/RC:C

CVSS Base Score:	4.9 (Medium)
Impact Subscore:	6.4
Exploitability Subscore:	4.4
CVSS Temporal Score:	3.6 (Low)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	3.6 (Low)

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

CVSS Base Score:	7.1 (High)
Impact Subscore:	5.9
Exploitability Subscore:	1.2
CVSS Temporal Score:	6.2 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.2 (Medium)

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

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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(152428);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/22");

  script_cve_id("CVE-2021-36949");
  script_xref(name:"IAVA", value:"2021-A-0433");

  script_name(english:"Security Update for Microsoft Azure Active Directory Connect (August 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The remote host has an application installed that is missing a security update.");
  script_set_attribute(attribute:"description", value:
"An authentication bypass exists in Microsoft Azure Active Directory Connect. An attacker with domain user credentials
may perform a man-in-the-middle between a domain controller and the Azure AD Connect server to exploit this
vulnerability.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36949
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?beec548c");
  # https://docs.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-version-history
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?67116170");
  script_set_attribute(attribute:"solution", value:
"Upgrade Azure Active Directory Connect to version 1.6.11.3, 2.0.8.0 or later.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:M/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:A/AC:H/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-2021-36949");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/08/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/08/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/08/10");

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

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

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

  script_dependencies("microsoft_azure_ad_connect_installed.nbin");
  script_require_keys("installed_sw/Microsoft Azure AD Connect");

  exit(0);
}

include('vcf.inc');

var app_info = vcf::get_app_info(app:'Microsoft Azure AD Connect', win_local:TRUE);

vcf::check_granularity(app_info:app_info, sig_segments:4);

var constraints = [
  { 'min_version': '0.0.0.0' ,'fixed_version' : '1.6.11.3' },
  { 'min_version': '2.0.0.0' ,'fixed_version' : '2.0.8.0' },
];

vcf::check_version_and_report(app_info:app_info, 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_aug_azure_ad_connect.nasl
Windows:
C:\ProgramData\Tenable\Nessus\nessus\plugins\smb_nt_ms21_aug_azure_ad_connect.nasl
Mac OS X:
/Library/Nessus/run/lib/nessus/plugins/smb_nt_ms21_aug_azure_ad_connect.nasl

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How to Run

Here is how to run the Security Update for Microsoft Azure Active Directory Connect (August 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 plugin family.
On the right side table select Security Update for Microsoft Azure Active Directory Connect (August 2021) plugin ID 152428.
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_aug_azure_ad_connect.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a smb_nt_ms21_aug_azure_ad_connect.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_aug_azure_ad_connect.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_aug_azure_ad_connect.nasl -t <IP/HOST>

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References

IAVA | Information Assurance Vulnerability Alert:

2021-A-0433

See also:

Similar and related Nessus plugins:

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146417 - Security Update for Microsoft Visual Studio Code npm-script Extension (Feb 2021)
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153474 - Microsoft Open Management Infrastructure < 1.6.8.1 Multiple Vulnerabilities
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153486 - Microsoft Open Management Infrastructure RCE (CVE-2021-38647)

Version

This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file smb_nt_ms21_aug_azure_ad_connect.nasl version 1.4. For more plugins, visit the Nessus Plugin Library.

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Security Update for Microsoft Azure Active Directory Connect (August 2021) - Nessus

Plugin Overview

Vulnerability Information

Synopsis

Description

Solution

Public Exploits

Risk Information

Plugin Source

How to Run

References

Version

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