MS KB2934088: Vulnerability in Internet Explorer Could Allow Remote Code Execution

#%NASL_MIN_LEVEL 999999

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

# @DEPRECATED@
#
# Disabled on 2014/03/11.  Deprecated by smb_nt_ms14-012.nasl
#

include("compat.inc");

if (description)
{
  script_id(72605);
  script_version("1.11");
  script_cvs_date("Date: 2018/07/27 18:38:15");

  script_cve_id("CVE-2014-0322");
  script_bugtraq_id(65551);
  script_xref(name:"CERT", value:"732479");
  script_xref(name:"MSKB", value:"2934088");

  script_name(english:"MS KB2934088: Vulnerability in Internet Explorer Could Allow Remote Code Execution");
  script_summary(english:"Checks if workarounds referenced in KB article have been applied.");

  script_set_attribute(attribute:"synopsis", value:"The remote host is affected by a remote code execution vulnerability.");
  script_set_attribute(
    attribute:"description",
    value:
"The remote host is missing one of the workarounds referenced in KB
2934088. 

The remote Internet Explorer install is affected by a use after free
vulnerability in the MSHTML CMarkup component.  By exploiting this flaw,
a remote, unauthenticated attacker could execute arbitrary code on the
remote host subject to the privileges of the user running the affected
application.");
  script_set_attribute(attribute:"see_also", value:"http://technet.microsoft.com/en-us/security/advisory/2934088");
  script_set_attribute(
    attribute:"solution",
    value:
"Apply the IE settings workarounds suggested by Microsoft in the
advisory, or apply the MSHTML Shim workaround in the Microsoft
'Fix it' solution."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2014/02/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2014/02/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/02/20");

  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:ie");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2014-2018 Tenable Network Security, Inc.");

  script_dependencies("microsoft_emet_installed.nasl", "smb_hotfixes.nasl");
  script_require_keys("SMB/Registry/Enumerated", "SMB/WindowsVersion", "SMB/IE/Version");
  script_require_ports(139, 445);
  exit(0);
}

# Deprecated.
exit(0, "This plugin has been deprecated. Use plugin #72930 (smb_nt_ms14-012.nasl) instead.");


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

if (hotfix_check_sp_range(vista:'2', win7:'1', win8:'0', win81:'0') <= 0) audit(AUDIT_OS_SP_NOT_VULN);

if (hotfix_check_server_core() == 1) audit(AUDIT_WIN_SERVER_CORE);

# only IE 9 and 10 affected
version = get_kb_item_or_exit("SMB/IE/Version");
v = split(version, sep:".", keep:FALSE);
if (int(v[0]) != 9 && int(v[0]) != 10) audit(AUDIT_INST_VER_NOT_VULN, "IE", version);

registry_init();

hklm = registry_hive_connect(hive:HKEY_LOCAL_MACHINE, exit_on_fail:TRUE);

systemroot = hotfix_get_systemroot();
if (!systemroot) audit(AUDIT_FN_FAIL, 'hotfix_get_systemroot');

guid = '{25408f0a-987b-4ab0-a5ac-2ddb89ff22cf}';
path = get_registry_value(handle:hklm, item:"SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\InstalledSDB\" + guid);
RegCloseKey(handle:hklm);

if (isnull(path)) path = systemroot + "\AppPatch\Custom\" + guid + '.sdb';

# Now make sure the file is in place
if (hotfix_file_exists(path:path))
{
  hotfix_check_fversion_end();
  exit(0, "The host is not affected since the Microsoft 'Fix it' has been applied.");
}

# hotfix_file_exists calls NetUseDel(close:FALSE), so we must reconnect
registry_init();

emet_info = '';

emet_installed = FALSE;
emet_with_ie   = FALSE;

if (!isnull(get_kb_item("SMB/Microsoft/EMET/Installed")))
  emet_installed = TRUE;

# Check if EMET is configured with IE.
# The workaround does not specifically ask to enable DEP
# but if IE is configured with EMET, dep is enabled by default.

emet_list = get_kb_list("SMB/Microsoft/EMET/*");
if (!isnull(emet_list))
{
  foreach entry (keys(emet_list))
  {
    if ("iexplore.exe" >< entry && "/dep" >< entry)
    {
      dep = get_kb_item(entry);
      if (!isnull(dep) && dep == 1)
        emet_with_ie = TRUE;
    }
  }
}

if (!emet_installed)
{
  emet_info =
  '\n  Microsoft Enhanced Mitigation Experience Toolkit (EMET) is not' +
  '\n  installed.';
}
else if (emet_installed)
{
  if (!emet_with_ie)
  {
    emet_info =
    '\n  Microsoft Enhanced Mitigation Experience Toolkit (EMET) is' +
    '\n  installed, however Internet Explorer is not configured with EMET.';
  }
}

info_user_settings = '';

# check mitigation per user
hku = registry_hive_connect(hive:HKEY_USERS, exit_on_fail:TRUE);
subkeys = get_registry_subkeys(handle:hku, key:'');

foreach key (subkeys)
{
  if ('.DEFAULT' >< key || 'Classes' >< key ||
     key =~ "^S-1-5-\d{2}$") # skip built-in accounts
    continue;

  mitigation = FALSE;

# "Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones"
  key_part_intranet = '\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\1\\CurrentLevel';
  key_part_internet = '\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\3\\CurrentLevel';

  value = get_registry_value(handle:hku, item:key + key_part_intranet);
  value1 = get_registry_value(handle:hku, item:key + key_part_internet);

  if (isnull(value) && isnull(value1))
    continue;

  # 0x00012000 = 73728 = High Security
  if (!isnull(value) && !isnull(value1) &&
     value == 73728 && value1 == 73728)
    mitigation = TRUE;

  # "Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone"
  key_part_intranet = '\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\1\\1400';
  key_part_internet = '\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\3\\1400';

  value = get_registry_value(handle:hku, item:key + key_part_intranet);
  value1 = get_registry_value(handle:hku, item:key + key_part_internet);

  # 1 = prompt, 3 = disable
  if (!isnull(value) && !isnull(value1) &&
     (value == 1 || value == 3) && (value1 == 1 || value1 == 3))
    mitigation = TRUE;

  if (!mitigation)
    info_user_settings += '\n    ' + key + ' (Active Scripting Enabled)';
}

RegCloseKey(handle:hku);

hklm = registry_hive_connect(hive:HKEY_LOCAL_MACHINE, exit_on_fail:TRUE);

# check if user settings have been overridden by what is in HKLM
# note: Security_HKLM_only can be set by group policy
value = get_registry_value(handle:hklm, item:'SOFTWARE\\Policies\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Security_HKLM_only');

if (info_user_settings != '' && !isnull(value) && value == 1)
{
  mitigation = FALSE;

# "Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones"
  key_part_intranet = 'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\1\\CurrentLevel';
  key_part_internet = 'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\3\\CurrentLevel';

  value = get_registry_value(handle:hklm, item:key_part_intranet);
  value1 = get_registry_value(handle:hklm, item:key_part_internet);

  # 0x00012000 = 73728 = High Security
  if (!isnull(value) && !isnull(value1) &&
     value == 73728 && value1 == 73728)
    mitigation = TRUE;

  # "Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone"
  key_part_intranet = 'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\1\\1400';
  key_part_internet = 'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings\\Zones\\3\\1400';

  value = get_registry_value(handle:hklm, item:key_part_intranet);
  value1 = get_registry_value(handle:hklm, item:key_part_internet);

  # 1 = prompt, 3 = disable
  if (!isnull(value) && !isnull(value1) &&
     (value == 1 || value == 3) && (value1 == 1 || value1 == 3))
    mitigation = TRUE;

  if (mitigation)
    info_user_settings = '';
}

RegCloseKey(handle:hklm);

close_registry();

if (info_user_settings != '')
{
  port = kb_smb_transport();

  if (report_verbosity > 0)
  {
    if (emet_info != '')
      report =
      '\n  The remote host is missing the MSHTML Shim workaround and the' +
      '\n  following users have vulnerable IE settings :' + info_user_settings + '\n' + emet_info + '\n';
    else
      report =
      '\n  The remote host is missing the MSHTML Shim workaround and the' +
      '\n  following users have vulnerable IE settings :' + info_user_settings + '\n';

    security_hole(port:port, extra:report);
  }
  else security_hole(port);
  exit(0);
}
else exit(0, "The host is not affected since a workaround has been applied.");