Security Updates for Microsoft Defender (April 2020)

#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(135718);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/02");

  script_cve_id("CVE-2020-1002");

  script_name(english:"Security Updates for Microsoft Defender (April 2020)");
  script_summary(english:"Checks the MpSigStub.exe version.");

  script_set_attribute(attribute:"synopsis", value:
"An antimalware application installed on the remote host is affected by
an elevation of privilege vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Microsoft Malware Protection Signature Update Stub (MpSigStub.exe) installed on the remote Windows host
is prior to 1.1.16638.0. It is, therefore, affected by a elevation of privilege vulnerability which could allow an
attacker who successfully exploited this vulnerability to elevate privileges on the system.");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1002
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d6966f51");
  script_set_attribute(attribute:"solution", value:
"Enable automatic updates to update the scan engine for the relevant antimalware applications or refer to the security
guidance for this CVE if Defender is in a disabled state. Refer to Knowledge Base Article 2510781 for information on how
to verify that MMPE has been updated.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/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:L/AC:L/PR:L/UI:N/S:U/C:N/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-2020-1002");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/04/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:windows_defender");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("smb_hotfixes.nasl");
  script_require_keys("SMB/Registry/Enumerated");
  script_require_ports(139, 445);

  exit(0);
}

include("audit.inc");
include("smb_func.inc");
include("smb_hotfixes_fcheck.inc");
include("smb_hotfixes.inc");
include("misc_func.inc");

app = 'Microsoft Malware Protection Signature Update Stub';
winroot = NULL;
mpsigstub_path = NULL;
version = NULL;
fix = "1.1.16638.0";

get_kb_item_or_exit("SMB/Registry/Enumerated");

winroot = hotfix_get_systemroot();
if (!winroot) exit(1, "Failed to get the system root.");

mpsigstub_path =  winroot + "\System32\MpSigStub.exe";

ver = hotfix_get_fversion(path:mpsigstub_path);
if (ver['error'] != HCF_OK) audit(AUDIT_NOT_DETECT, app);

version = join(ver['value'], sep:'.');

if (ver_compare(ver:version, fix:fix) < 0)
{
  report =  '\n  Product           : ' + app;
  report += '\n  Path              : ' + mpsigstub_path;
  report += '\n  Installed version : ' + version;
  report += '\n  Fixed version     : ' + fix;
  report += '\n';

  security_report_v4(port:0, extra:report, severity:SECURITY_WARNING);
}
else audit(AUDIT_INST_VER_NOT_VULN, app, version);