Security Update for .NET Core (January 2018)

#
# (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(105730);
  script_version("1.8");
  script_cvs_date("Date: 2019/11/08");

  script_cve_id("CVE-2018-0764", "CVE-2018-0786");

  script_name(english:"Security Update for .NET Core (January 2018)");
  script_summary(english:"Checks for Windows Install of .NET Core.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by a .NET Core runtime
vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote Windows host has an installation of .NET Core
with a version less than 2.0.5. Therefore, the host is affected
by multiple vulnerabilities :

  - A security feature bypass in X509 Certificate Validation
    allows an attacker to present a certificate that is
    marked as invalid for a specific use, but a component
    uses it for that purpose. (CVE-2018-0786)

  - A denial of service vulnerability exists due to improper
     processing of XML documents. An attacker who
     successfully exploited this vulnerability could cause
     a denial of service against a .NET application. A
     remote unauthenticated attacker could exploit this
     vulnerability by issuing specially crafted requests
     to a .NET Core application. (CVE-2018-0764)");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/51");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/announcements/issues/52");
  # https://blogs.msdn.microsoft.com/dotnet/2018/01/09/net-core-january-2018-update/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ebdb4bc7");
  # https://github.com/dotnet/core/blob/master/release-notes/1.0/1.0.9.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6ee5ffe3");
  # https://github.com/dotnet/core/blob/master/release-notes/1.1/1.1.6.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e1e826f0");
  # https://github.com/dotnet/core/blob/master/release-notes/2.0/2.0.5.md
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9a103486");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0786
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3759d74b");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0764
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cf7d5ce3");
  script_set_attribute(attribute:"solution", value:
"Update to .NET Core Runtime version 1.09 / 1.1.6 / 2.0.5 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-0786");

  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:"2018/01/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/10");

  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) 2018-2019 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");
  script_require_ports(139, 445);

  exit(0);
}

include("global_settings.inc");
include("audit.inc");
include("install_func.inc");
include("misc_func.inc");
include("smb_func.inc");

appname = '.NET Core Windows';
port = kb_smb_transport();

installs = get_installs(app_name:appname, exit_if_not_found:TRUE);

report = '';

foreach install (installs[1])
{
  version = install['version'];
  path = install['path'];

  fix = '';
  # Affected: 1.0.x < 1.0.9 / 1.1.x < 1.1.6 / 2.0.x < 2.0.5
  if      (version =~ '^2\\.0\\.') fix = '2.0.5.26021';
  else if (version =~ '^1\\.1\\.') fix = '1.1.6.1663';
  else if (version =~ '^1\\.0\\.') fix = '1.0.9.5018';

  if (fix != '' && ver_compare(ver:version, fix:fix) < 0)
  {
    report +=
      '\n  Path              : ' + path +
      '\n  Installed version : ' + version +
      '\n  Fixed version     : ' + fix +
      '\n';
  }
}

if (report != '')
{
  security_report_v4(port:port, severity:SECURITY_WARNING, extra:report);
  exit(0);
}

audit(AUDIT_INST_VER_NOT_VULN, appname);