Security Update for .NET Core (January 2021)

#
# (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(145041);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/12/07");

  script_cve_id("CVE-2021-1723");
  script_xref(name:"CEA-ID", value:"CEA-2021-0001");

  script_name(english:"Security Update for .NET Core (January 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by a .NET Core denial of service (DoS) vulnerability.");
  script_set_attribute(attribute:"description", value:
"The Microsoft .NET Core installation on the remote host is version 3.1.x < 3.1.11 or 5.x prior to 5.0.2. It is,
therefore, affected by a denial of service (DoS) vulnerability in the way Kestrel parses HTTP/2 requests. An
unauthenticated, remote attacker can exploit this issue, by sending a specially crafted requests to the .NET Core
application, to cause a DoS condition.");
  script_set_attribute(attribute:"see_also", value:"https://dotnet.microsoft.com/download/dotnet-core/3.1");
  script_set_attribute(attribute:"see_also", value:"https://dotnet.microsoft.com/download/dotnet/5.0");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/171");
  # https://msrc.microsoft.com/update-guide/en-us/vulnerability/CVE-2021-1723
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9175240f");
  script_set_attribute(attribute:"solution", value:
"Update .NET Core, remove vulnerable packages and refer to vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/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:N/UI:N/S:U/C:N/I:N/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-2021-1723");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/01/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/01/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/01/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:.net_core");
  script_end_attributes();

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

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

  script_dependencies("microsoft_dotnet_core_win.nbin");
  script_require_keys("installed_sw/.NET Core Windows");

  exit(0);
}

include('vcf.inc');

app = '.NET Core Windows';
app_info = vcf::get_app_info(app:app, win_local:TRUE);

constraints = [
  { 'min_version' : '3.1', 'fixed_version' : '3.1.11' },
  { 'min_version' : '5.0', 'fixed_version' : '5.0.2' }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_WARNING);