Security Updates for Microsoft Office Online Server and Microsoft Office Web Apps (October 2020)

#
# (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(141421);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/12/05");

  script_cve_id("CVE-2020-16929", "CVE-2020-16931", "CVE-2020-16932");
  script_xref(name:"MSKB", value:"4462175");
  script_xref(name:"MSKB", value:"4486674");
  script_xref(name:"MSKB", value:"4486689");
  script_xref(name:"MSFT", value:"MS20-4462175");
  script_xref(name:"MSFT", value:"MS20-4486674");
  script_xref(name:"MSFT", value:"MS20-4486689");
  script_xref(name:"IAVA", value:"2020-A-0454-S");
  script_xref(name:"CEA-ID", value:"CEA-2020-0126");

  script_name(english:"Security Updates for Microsoft Office Online Server and Microsoft Office Web Apps (October 2020)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft Office Web Apps installation on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office Web Apps installation on the remote
host is missing security updates. It is, therefore, affected
by multiple vulnerabilities :

  - A remote code execution vulnerability exists in
    Microsoft Excel software when the software fails to
    properly handle objects in memory. An attacker who
    successfully exploited the vulnerability could run
    arbitrary code in the context of the current user. If
    the current user is logged on with administrative user
    rights, an attacker could take control of the affected
    system. An attacker could then install programs; view,
    change, or delete data; or create new accounts with full
    user rights.  (CVE-2020-16929, CVE-2020-16931,
    CVE-2020-16932)");
  # https://support.microsoft.com/en-us/help/4486689/security-update-for-office-web-apps-server-2013-oct-13-2020
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?29683456");
  # https://support.microsoft.com/en-us/help/4486674/security-update-for-office-online-server-october-13-2020
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?998c805a");
  # https://support.microsoft.com/en-us/help/4462175/security-update-for-sharepoint-2010-excel-web-app-october-13-2020
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1a69c896");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:  
  -KB4486689
  -KB4486674
  -KB4462175");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  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:N/UI:R/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-2020-16932");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/10/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/10/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:office_web_apps");
  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) 2020-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("office_installed.nasl", "microsoft_owa_installed.nbin", "microsoft_office_compatibility_pack_installed.nbin", "smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('smb_func.inc');
include('smb_hotfixes.inc');
include('smb_hotfixes_fcheck.inc');
include('install_func.inc');

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

bulletin = 'MS20-10';
kbs = make_list('4462175', '4486674', '4486689');
if (get_kb_item('Host/patch_management_checks')) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_WARNING);

get_kb_item_or_exit('SMB/Registry/Enumerated', exit_code:1);

port = kb_smb_transport();

# Get installs of Office Web Apps
owa_installs = get_installs(app_name:'Microsoft Office Web Apps');

if (!empty_or_null(owa_installs))
{
  foreach owa_install (owa_installs[1])
  {
    if (owa_install['Product'] == '2010')
    {
      owa_2010_path = owa_install['path'];
      owa_2010_sp = owa_install['SP'];
    }
    else if (owa_install['Product'] == '2013')
    {
      owa_2013_path = owa_install['path'];
      owa_2013_sp = owa_install['SP'];
    }
    else if (owa_install['Product'] == '2016')
    {
      oos_path = owa_install['path'];
      oos_sp = owa_install['SP'];
    }
  }
}
vuln = FALSE;

####################################################################
# Office Web Apps 2010 SP2
####################################################################
if (owa_2010_path && (!isnull(owa_2010_sp) && owa_2010_sp == '2'))
{
  path = hotfix_append_path(path:owa_2010_path, value:'14.0\\WebServices\\ConversionService\\Bin\\Converter\\1033');
  if (hotfix_check_fversion(file:'xlsrv.dll', version:'14.0.7261.5000', min_version:'14.0.0.0', path:path, kb:'4462175', product:'Office Web Apps 2010') == HCF_OLDER)
    vuln = TRUE;
}

####################################################################
# Office Web Apps 2013 SP1
####################################################################
if (owa_2013_path && (!isnull(owa_2013_sp) && owa_2013_sp == '1'))
{
  path = hotfix_append_path(path:owa_2013_path, value:'WordConversionService\\bin\\Converter');
  if (hotfix_check_fversion(file:'sword.dll', version:'15.0.5285.1000', min_version:'15.0.0.0', path:path, kb:'4486689', product:'Office Web Apps 2013') == HCF_OLDER)
    vuln = TRUE;
}

####################################################################
# Office Online Server
####################################################################
if (oos_path && (!isnull(oos_sp) && oos_sp == '0'))
{
  path = hotfix_append_path(path:oos_path, value:'WordConversionService\\bin\\Converter');
  if (hotfix_check_fversion(file:'sword.dll', version:'16.0.10367.20000', min_version:'16.0.0.0', path:path, kb:'4486674', product:'Office Online Server') == HCF_OLDER)
  vuln = TRUE;
}

if (vuln)
{
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_warning();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, 'affected');
}