Microsoft Office 2013 Remote Code Execution Vulnerability (KB4484435)

# Copyright (C) 2020 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.817469");
  script_version("2021-08-11T12:01:46+0000");
  script_cve_id("CVE-2020-16930");
  script_tag(name:"cvss_base", value:"6.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_tag(name:"last_modification", value:"2021-08-11 12:01:46 +0000 (Wed, 11 Aug 2021)");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-10-20 13:24:00 +0000 (Tue, 20 Oct 2020)");
  script_tag(name:"creation_date", value:"2020-10-14 12:02:29 +0530 (Wed, 14 Oct 2020)");
  script_name("Microsoft Office 2013 Remote Code Execution Vulnerability (KB4484435)");

  script_tag(name:"summary", value:"This host is missing an important security
  update according to Microsoft KB4484435");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present
  on the target host.");

  script_tag(name:"insight", value:"A remote code execution vulnerability exists
  in Microsoft Excel because it fails to properly handle objects in memory.");

  script_tag(name:"impact", value:"Successful exploitation will allow an attacker
  to execute arbitrary code in the context of the current user.");

  script_tag(name:"affected", value:"Microsoft Office 2013.");

  script_tag(name:"solution", value:"The vendor has released updates. Please see the references for more information.");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"executable_version");
  script_xref(name:"URL", value:"https://support.microsoft.com/en-us/help/4484435");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
  script_family("Windows : Microsoft Bulletins");
  script_dependencies("secpod_office_products_version_900032.nasl");
  script_require_ports(139, 445);
  script_mandatory_keys("MS/Office/Ver");
  exit(0);
}

include("smb_nt.inc");
include("secpod_reg.inc");
include("version_func.inc");
include("secpod_smb_func.inc");

## MS Office
offVer = get_kb_item("MS/Office/Ver");
if(!offVer){
  exit(0);
}

if(offVer =~ "^15.*")
{
  dllPath = registry_get_sz(key:"SOFTWARE\Microsoft\Windows\CurrentVersion",
                item:"CommonFilesDir");
  if(dllPath)
  {
    vbVer = fetch_file_version(sysPath:dllPath, file_name:"Microsoft Shared\VBA\VBA7\VBE7.DLL");
    if(!vbVer){
      exit(0);
    }

    if(version_in_range(version:vbVer, test_version:"7.0", test_version2:"7.01.1099"))
    {
      report = report_fixed_ver(file_checked: dllPath + "Microsoft Shared\VBA\VBA7\VBE7.DLL",
                            file_version:vbVer, vulnerable_range:"7.0 - 7.01.1099");
      security_message(data:report);
      exit(0);
    }
  }
}
exit(99);