Security Updates for Microsoft Exchange Server (December 2025)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(278114);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/27");

  script_cve_id("CVE-2025-64666", "CVE-2025-64667");
  script_xref(name:"MSFT", value:"MS25-5071873");
  script_xref(name:"MSFT", value:"MS25-5071874");
  script_xref(name:"MSFT", value:"MS25-5071875");
  script_xref(name:"MSFT", value:"MS25-5071876");
  script_xref(name:"MSKB", value:"5071873");
  script_xref(name:"MSKB", value:"5071874");
  script_xref(name:"MSKB", value:"5071875");
  script_xref(name:"MSKB", value:"5071876");
  script_xref(name:"IAVA", value:"2025-A-0913");

  script_name(english:"Security Updates for Microsoft Exchange Server (December 2025)");

  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 a security update. It is, therefore, affected by
multiple vulnerabilities as referenced in the December, 2025 security bulletin.

  - Improper input validation in Microsoft Exchange Server allows an authorized attacker to elevate privileges
    over a network. (CVE-2025-64666)

  - User interface (ui) misrepresentation of critical information in Microsoft Exchange Server allows an
    unauthorized attacker to perform spoofing over a network. (CVE-2025-64667)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://learn.microsoft.com/en-us/exchange/new-features/updates?source=recommendations#exchange-server-2019
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?8d7cfad1");
  # https://learn.microsoft.com/en-us/exchange/new-features/updates?source=recommendations#exchange-server-2016
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0240eb20");
  # https://learn.microsoft.com/en-us/exchange/new-features/build-numbers-and-release-dates
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0d6169eb");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:
  -KB5071873
  -KB5071874
  -KB5071875
  -KB5071876");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/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-2025-64666");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/12/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/12/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/12/10");

  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:"cpe", value:"cpe:/a:microsoft:exchange_server:subscription_edition");
  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) 2025-2026 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.inc');
include('vcf_extras_microsoft.inc');

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

var constraints = [
  { 'fixed_version' : '15.1.2507.63', 'product' : '2016', 'cu' : 23, 'unsupported_cu' : 22, 'kb' : '5071873' },
  { 'fixed_version' : '15.2.1544.37', 'product' : '2019', 'cu' : 14, 'unsupported_cu' : 13, 'kb' : '5071874' },
  { 'fixed_version' : '15.2.1748.42', 'product' : '2019', 'cu' : 15, 'unsupported_cu' : 13, 'kb' : '5071875' },
  { 'fixed_version' : '15.2.2562.35', 'product' : 'Subscription Edition', 'cu' : 0, 'kb' : '5071876' }
];

vcf::microsoft::exchange::check_version_and_report(
  app_info:app_info,
  bulletin:'MS25-12',
  constraints:constraints,
  severity:SECURITY_HOLE
);