Vulnerabilities > CVE-2017-8558 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Microsoft products

047910
CVSS 9.3 - CRITICAL
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
microsoft
CWE-119
critical
nessus
exploit available

Summary

The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on 32-bit versions of Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703 does not properly scan a specially crafted file leading to memory corruption. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability".

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.

Exploit-Db

descriptionMicrosoft MsMpEng - mpengine x86 Emulator Heap Corruption in VFS API. CVE-2017-8558. Dos exploit for Windows platform
fileexploits/windows/dos/42264.txt
idEDB-ID:42264
last seen2017-06-27
modified2017-06-27
platformwindows
port
published2017-06-27
reporterExploit-DB
sourcehttps://www.exploit-db.com/download/42264/
titleMicrosoft MsMpEng - mpengine x86 Emulator Heap Corruption in VFS API
typedos

Nessus

NASL familyWindows
NASL idMICROSOFT_MPENG_1_1_13903.NASL
descriptionThe version of Microsoft Malware Protection Engine (MMPE) installed on the remote Windows host is prior to 1.1.13903.0. It is, therefore, affected by a remote code execution vulnerability due to improper handling of files during scanning. An unauthenticated, remote attacker can exploit this, via a specially crafted file, to execute arbitrary code in the security context of the LocalSystem account. Note that only x86 or 32-bit based versions of the MMPE are affected by this vulnerability. Nessus has checked if a vulnerable version of MMPE is being used by any of the following applications : - Microsoft Forefront Endpoint Protection 2010. - Microsoft Endpoint Protection. - Microsoft Forefront Security for SharePoint. - Microsoft System Center Endpoint Protection. - Microsoft Security Essentials. - Windows Defender for Windows 7, Windows 8.1, Windows RT 8.1, Windows 10, Windows 10 1511, Windows 10 1607, Windows 10 1703, and Windows Server 2016. - Windows Intune Endpoint Protection.
last seen2020-06-01
modified2020-06-02
plugin id101027
published2017-06-23
reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/101027
titleMicrosoft Malware Protection Engine < 1.1.13903 RCE
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(101027);
  script_version("1.8");
  script_cvs_date("Date: 2019/11/13");

  script_cve_id("CVE-2017-8558");
  script_bugtraq_id(99262);

  script_name(english:"Microsoft Malware Protection Engine < 1.1.13903 RCE");
  script_summary(english:"Checks engine version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote host has an antimalware application installed that is
affected by a remote code execution vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Microsoft Malware Protection Engine (MMPE) installed on
the remote Windows host is prior to 1.1.13903.0. It is, therefore,
affected by a remote code execution vulnerability due to improper
handling of files during scanning. An unauthenticated, remote attacker
can exploit this, via a specially crafted file, to execute arbitrary
code in the security context of the LocalSystem account. Note that
only x86 or 32-bit based versions of the MMPE are affected by this
vulnerability.

Nessus has checked if a vulnerable version of MMPE is being used by
any of the following applications :

  - Microsoft Forefront Endpoint Protection 2010.

  - Microsoft Endpoint Protection.

  - Microsoft Forefront Security for SharePoint.

  - Microsoft System Center Endpoint Protection.

  - Microsoft Security Essentials.

  - Windows Defender for Windows 7, Windows 8.1, Windows RT
    8.1, Windows 10, Windows 10 1511, Windows 10 1607,
    Windows 10 1703, and Windows Server 2016.

  - Windows Intune Endpoint Protection.");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8558
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cc6c4cd9");
  script_set_attribute(attribute:"solution", value:
"Enable automatic updates to update the scan engine for the relevant
antimalware applications.");
  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:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-8558");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/06/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/23");

  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:malware_protection_engine");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("smb_func.inc");

get_kb_item_or_exit("SMB/Registry/Enumerated");
arch = get_kb_item_or_exit('SMB/ARCH');
# Only x86 or 32-bit versions of the Malware Protection Engine are affected.
if (arch == "x64") audit(AUDIT_ARCH_NOT, "x86", arch);

# indicates if any antimalware products were found. this is used
# to determine whether or not the plugin should check if defender is affected
antimalware_installed = FALSE;

# Connect to the appropriate share.
port    =  kb_smb_transport();
login   =  kb_smb_login();
pass    =  kb_smb_password();
domain  =  kb_smb_domain();

if(! smb_session_init()) audit(AUDIT_FN_FAIL, 'smb_session_init');

rc = NetUseAdd(login:login, password:pass, domain:domain, share:"IPC$");
if (rc != 1)
{
  NetUseDel();
  audit(AUDIT_SHARE_FAIL, "IPC$");
}

# Connect to remote registry.
hklm = RegConnectRegistry(hkey:HKEY_LOCAL_MACHINE);
if (isnull(hklm))
{
  NetUseDel();
  audit(AUDIT_REG_FAIL);
}

# Figure out where it is installed.
path = NULL;
info = '';
info2 = '';
engine_version = NULL;

fixed_engine_version = "1.1.13903.0";
last_vulnerable = "1.1.13804.0";

# Forefront Client Security (either both or neither of these will be in the KB)
engine_version = get_kb_item("Antivirus/Forefront_Client_Security/engine_version");
fcs_path = get_kb_item("Antivirus/Forefront_Client_Security/path");
if (!isnull(engine_version))
{
  antimalware_installed = TRUE;

  if (ver_compare(ver:engine_version, fix:last_vulnerable) <= 0)
  {
    info +=
      '\n  Product           : Microsoft Forefront Client Security'+
      '\n  Path              : ' + fcs_path +
      '\n  Installed version : ' + engine_version +
      '\n  Fixed version     : ' + fixed_engine_version + '\n';
  }
  else info2 += 'Microsoft Forefront Client Security with MMPE version '+ engine_version + ". ";
}

# Microsoft Security Essentials
# Forefront Endpoint Protection
# System Center Endpoint Protection
engine_version = NULL;

NetUseDel(close:FALSE);
rc = NetUseAdd(login:login, password:pass, domain:domain, share:"IPC$");
if (rc != 1)
{
  NetUseDel();
  audit(AUDIT_SHARE_FAIL, "IPC$");
}

# Connect to remote registry again.
hklm = RegConnectRegistry(hkey:HKEY_LOCAL_MACHINE);
if (isnull(hklm))
{
  NetUseDel();
  audit(AUDIT_REG_FAIL);
}

key = "SOFTWARE\Microsoft\Microsoft Antimalware\Signature Updates";
key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
if (!isnull(key_h))
{
  value = RegQueryValue(handle:key_h, item:"EngineVersion");
  if (!isnull(value)) engine_version = value[1];

  RegCloseKey(handle:key_h);
}

path = NULL;
key = "SOFTWARE\Microsoft\Microsoft Antimalware";
key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
if (!isnull(key_h))
{
  value = RegQueryValue(handle:key_h, item:"InstallLocation");
  if (!isnull(value)) path = value[1];

  RegCloseKey(handle:key_h);
}

if(!isnull(path))
{
  found = 0;
  # Check if the main exe exists.
  share = ereg_replace(pattern:"^([A-Za-z]):.*", replace:"\1$", string:path);
  exe =  ereg_replace(pattern:"^[A-Za-z]:(.*)", replace:"\1\MsMpEng.exe", string:path);
  NetUseDel(close:FALSE);
  rc = NetUseAdd(login:login, password:pass, domain:domain, share:share);
  if (rc != 1)
  {
    NetUseDel();
    audit(AUDIT_SHARE_FAIL, share);
  }
  fh = CreateFile(
    file:exe,
    desired_access:GENERIC_READ,
    file_attributes:FILE_ATTRIBUTE_NORMAL,
    share_mode:FILE_SHARE_READ,
    create_disposition:OPEN_EXISTING
  );
  if (!isnull(fh))
  {
    antimalware_installed = TRUE;
    found = 1;
    CloseFile(handle:fh);
  }

  if (found && !isnull(engine_version))
  {
    if (ver_compare(ver:engine_version, fix:last_vulnerable) <= 0)
    {
      info +=
       '\n  Product           : Microsoft Security Essentials / Forefront Endpoint Protection / System Center Endpoint Protection'+
       '\n  Path              : ' + share[0] + ':' + exe +
       '\n  Installed version : ' + engine_version +
       '\n  Fixed version     : ' + fixed_engine_version + '\n';
    }
    else info2 += 'Microsoft Security Essentials / Forefront Endpoint Protection / System Center Endpoint Protection with MMPE version ' + engine_version + ". ";
  }
}

# Microsoft Windows Defender
# defender is apparently disabled when other antimalware products are installed,
# so it will only be checked if the plugin hasn't detected other products are present
if (!antimalware_installed)
{
  defender_enabled = TRUE;
  engine_version = NULL;

  # Check if Windows Defender is disabled via group policy
  key = "SOFTWARE\Policies\Microsoft\Windows Defender";
  key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
  if (!isnull(key_h))
  {
    value = RegQueryValue(handle:key_h, item:"DisableAntiSpyware");
    if (!isnull(value))
    {
      if (value[1] > 0)
      {
        defender_enabled = FALSE;
      }
    }
    RegCloseKey(handle:key_h);
  }
  key = "SOFTWARE\Microsoft\Windows Defender";
  key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
  if (!isnull(key_h))
  {
    value = RegQueryValue(handle:key_h, item:"DisableAntiSpyware");
    if (!isnull(value))
    {
      if (value[1] > 0)
      {
        defender_enabled = FALSE;
      }
    }
    RegCloseKey(handle:key_h);
  }
  if (defender_enabled)
  {
    key = "SOFTWARE\Microsoft\Windows Defender\Signature Updates";
    key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
    if (!isnull(key_h))
    {
      value = RegQueryValue(handle:key_h, item:"EngineVersion");
      if (!isnull(value)) engine_version = value[1];

      RegCloseKey(handle:key_h);
    }

    path = NULL;
    key = "SOFTWARE\Microsoft\Windows Defender\Signature Updates";
    key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
    if (!isnull(key_h))
    {
      value = RegQueryValue(handle:key_h, item:"SignatureLocation");
      if (!isnull(value)) path = value[1];

      RegCloseKey(handle:key_h);
    }

    if(!isnull(path))
    {
      found = 0;
      defender_dll = NULL;
      # Check the version of the main exe.
      share = ereg_replace(pattern:"^([A-Za-z]):.*", replace:"\1$", string:path);
      # this is the path smb_kb4022344.nasl checks
      dll1 =  ereg_replace(pattern:"^[A-Za-z]:(.+Windows Defender\\Definition Updates).+", replace:"\1\Default\MpEngine.dll", string:path);
      # this path works for Windows Defender on Windows 8
      dll2 =  ereg_replace(pattern:"^[A-Za-z]:(.+)$", replace:"\1\MpEngine.dll", string:path);
      NetUseDel(close:FALSE);
      rc = NetUseAdd(login:login, password:pass, domain:domain, share:share);
      if (rc != 1)
      {
        NetUseDel();
        audit(AUDIT_SHARE_FAIL, share);
      }
      fh = CreateFile(
        file:dll1,
        desired_access:GENERIC_READ,
        file_attributes:FILE_ATTRIBUTE_NORMAL,
        share_mode:FILE_SHARE_READ,
        create_disposition:OPEN_EXISTING
      );
      if (!isnull(fh))
      {
        found =1 ;
        defender_dll = share[0] + ':' + dll1;
        CloseFile(handle:fh);
      }

      if (found == 0)
      {
        fh = CreateFile(
          file:dll2,
          desired_access:GENERIC_READ,
          file_attributes:FILE_ATTRIBUTE_NORMAL,
          share_mode:FILE_SHARE_READ,
          create_disposition:OPEN_EXISTING
        );
        if (!isnull(fh))
        {
          found =1 ;
          defender_dll = share[0] + ':' + dll2;
          CloseFile(handle:fh);
        }
      }

      if (found && !isnull(engine_version))
      {
        if (ver_compare(ver:engine_version, fix:last_vulnerable) <= 0)
        {
          info +=
           '\n  Product           : Microsoft Windows Defender'+
           '\n  Path              : ' + defender_dll +
           '\n  Installed version : ' + engine_version +
           '\n  Fixed version     : ' + fixed_engine_version + '\n';
        }
        else info2 += 'Microsoft Windows Defender with MMPE version ' + engine_version + ". ";
      }
    }
  }
}

RegCloseKey(handle:hklm);
NetUseDel();

if (info)
{
  report = '\n' +
    "Nessus found following vulnerable product(s) installed :" +'\n'+
    info;
  security_report_v4(severity:SECURITY_HOLE, port:port, extra:report);

  exit(0);
}
else if(info2) exit(0,"The following instance(s) of MMPE are installed and not vulnerable : "+ info2);
else exit(0, "Nessus could not find evidence of affected Microsoft antimalware products installed.");