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nessusThis script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.SMB_NT_MS21_APR_EXCHANGE.NASL
HistoryApr 13, 2021 - 12:00 a.m.

Security Updates for Microsoft Exchange Server (April 2021)

2021-04-1300:00:00
This script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
163

CVSS2

10

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS3

9.8

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

AI Score

9.6

Confidence

High

EPSS

0.973

Percentile

99.9%

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

  • A remote code execution vulnerability. An attacker could exploit this to execute unauthorized arbitrary code. (CVE-2021-28483, CVE-2021-28482, CVE-2021-28481, CVE-2021-28480, CVE-2021-34473)

  • An elevation of privilege vulnerability. An attacker can exploit this to gain elevated privileges. (CVE-2021-34523)

  • An information disclosure vulnerability. An attacker can exploit this to disclose potentially sensitive information. (CVE-2021-33766)

#%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(148476);
  script_version("1.16");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/06/06");

  script_cve_id(
    "CVE-2021-28480",
    "CVE-2021-28481",
    "CVE-2021-28482",
    "CVE-2021-28483",
    "CVE-2021-33766",
    "CVE-2021-34473",
    "CVE-2021-34523"
  );
  script_xref(name:"MSKB", value:"5001779");
  script_xref(name:"MSFT", value:"MS21-5001779");
  script_xref(name:"IAVA", value:"2021-A-0160-S");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2021/11/17");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/02/01");
  script_xref(name:"CEA-ID", value:"CEA-2021-0040");
  script_xref(name:"CEA-ID", value:"CEA-2021-0022");
  script_xref(name:"CEA-ID", value:"CEA-2021-0021");

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

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

  - A remote code execution vulnerability. An attacker could exploit this to
    execute unauthorized arbitrary code. (CVE-2021-28483, CVE-2021-28482,
    CVE-2021-28481, CVE-2021-28480, CVE-2021-34473)

  - An elevation of privilege vulnerability. An attacker can exploit this to
  gain elevated privileges. (CVE-2021-34523)

  - An information disclosure vulnerability. An attacker can exploit this to
  disclose potentially sensitive information. (CVE-2021-33766)");
  # https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-microsoft-exchange-server-2019-2016-and-2013-april-13-2021-kb5001779-8e08f3b3-fc7b-466c-bbb7-5d5aa16ef064
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3bdeeea7");
  # https://msrc-blog.microsoft.com/2021/04/13/april-2021-update-tuesday-packages-now-available/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b66291c9");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:
  -KB5001779");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/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:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-34473");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2021-28481");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Microsoft Exchange ProxyShell RCE');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/04/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/04/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/04/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server:2016");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server:2019");
  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) 2021-2024 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' : '2013',
    'unsupported_cu' : 22,
    'cu' : 23,
    'min_version': '15.00.1497.0',
    'fixed_version': '15.00.1497.18',
    'kb': '5001779'
  },
  {
    'product' : '2016',
    'unsupported_cu' : 18,
    'cu' : 20,
    'min_version': '15.01.2176.0',
    'fixed_version': '15.01.2176.14',
    'kb': '5001779'
  },
  {
    'product': '2016',
    'unsupported_cu': 18,
    'cu' : 20,
    'min_version': '15.01.2242.0',
    'fixed_version': '15.01.2242.10',
    'kb': '5001779'
  },
  {
    'product' : '2019',
    'unsupported_cu' : 7,
    'cu' : 8,
    'min_version': '15.02.792.0',
    'fixed_version': '15.02.792.15',
    'kb': '5001779'
  },
  {
    'product' : '2019',
    'unsupported_cu' : 7,
    'cu' : 9,
    'min_version': '15.02.858.0',
    'fixed_version': '15.02.858.12',
    'kb': '5001779'
  }
];

vcf::microsoft::exchange::check_version_and_report
(
  app_info:app_info,
  bulletin:'MS21-05',
  constraints:constraints,
  severity:SECURITY_HOLE
);
VendorProductVersionCPE
microsoftexchange_server2016cpe:/a:microsoft:exchange_server:2016
microsoftexchange_server2019cpe:/a:microsoft:exchange_server:2019

CVSS2

10

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS3

9.8

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

AI Score

9.6

Confidence

High

EPSS

0.973

Percentile

99.9%