Security Updates for Microsoft Office Web Apps (August 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(111699);
  script_version("1.6");
  script_cvs_date("Date: 2019/11/04");

  script_cve_id("CVE-2018-8378");
  script_xref(name:"MSKB", value:"4032220");
  script_xref(name:"MSKB", value:"4022238");
  script_xref(name:"MSFT", value:"MS18-4032220");
  script_xref(name:"MSFT", value:"MS18-4022238");

  script_name(english:"Security Updates for Microsoft Office Web Apps (August 2018)");
  script_summary(english:"Checks for Microsoft security updates.");

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

  - An information disclosure vulnerability exists when
    Microsoft Office software reads out of bound memory due
    to an uninitialized variable, which could disclose the
    contents of memory. An attacker who successfully
    exploited the vulnerability could view out of bound
    memory. Exploitation of the vulnerability requires that
    a user open a specially crafted file with an affected
    version of Microsoft Office software. The security
    update addresses the vulnerability by properly
    initializing the affected variable. (CVE-2018-8378)");
  # https://support.microsoft.com/en-us/help/4022238/description-of-the-security-update-for-office-web-apps-server-2013-aug
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2292b1eb");
  # https://support.microsoft.com/en-us/help/4032220/description-of-the-security-update-for-sharepoint-server-2010-office-w
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?faf56be8");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:
  -KB4022238
  -KB4032220");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
  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:N/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-2018-8378");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/08/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/14");

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

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

  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("office_installed.nasl", "microsoft_owa_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("audit.inc");
include("smb_func.inc");
include("smb_hotfixes.inc");
include("smb_hotfixes_fcheck.inc");
include("smb_reg_query.inc");
include("misc_func.inc");
include("install_func.inc");

get_kb_item_or_exit("SMB/MS_Bulletin_Checks/Possible");

bulletin = "MS18-08";
kbs = make_list(
  "4032220",
  "4022238"
);

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);

registry_init();
hklm = registry_hive_connect(hive:HKEY_LOCAL_MACHINE, exit_on_fail:TRUE);
global_var office_online_server_path = get_registry_value(
  handle : hklm,
  item   : "SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Office16.WacServer\InstallLocation"
);
RegCloseKey(handle:hklm);
close_registry(close:FALSE);

port = kb_smb_transport();

function perform_owa_checks()
{
  local_var owa_installs, owa_install;
  local_var owa_2010_path, owa_2010_sp;
  local_var owa_2013_path, owa_2013_sp;
  local_var path;
  local_var vuln;

  # 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"];
      }
    }
  }

  ####################################################################
  # 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\PowerPoint\Bin\Converter");
    if (hotfix_check_fversion(file:"ppserver.dll", version:"14.0.7211.5000", min_version:"14.0.0.0", path:path, kb:"4032220", 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:"15.0.5059.1000", min_version:"15.0.0.0", path:path, kb:"4022238", product:"Office Web Apps 2013") == HCF_OLDER)
      vuln = TRUE;
  }
  return vuln;
}

global_var vuln = 0;
vuln += perform_owa_checks();

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');
}