Vulnerabilities > CVE-2018-8412 - Improper Input Validation vulnerability in Microsoft Office for mac 2016

047910
CVSS 7.8 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
local
low complexity
microsoft
CWE-20
nessus

Summary

An elevation of privilege vulnerability exists when the Microsoft AutoUpdate (MAU) application for Mac improperly validates updates before executing them, aka "Microsoft (MAU) Office Elevation of Privilege Vulnerability." This affects Microsoft Office.

Vulnerable Configurations

Part Description Count
Application
Microsoft
1

Common Weakness Enumeration (CWE)

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.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

NASL familyMacOS X Local Security Checks
NASL idMACOS_MS18_AUG_OFFICE.NASL
descriptionThe Microsoft Office 2016 application installed on the remote macOS or Mac OS X host is missing a security update. It is, therefore, affected by the following vulnerabilities: - An elevation of privilege vulnerability exists when the Microsoft AutoUpdate (MAU) application for Mac improperly validates updates before executing them. An attacker who successfully exploited the vulnerability who already has the ability to execute code on a system could elevate privileges. (CVE-2018-8412) - 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. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. (CVE-2018-8375) - An information disclosure vulnerability exists when Microsoft Excel improperly discloses the contents of its memory. An attacker who exploited the vulnerability could use the information to compromise the user
last seen2020-06-01
modified2020-06-02
plugin id111682
published2018-08-14
reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/111682
titleSecurity Update for Microsoft Office (Auguest 2018) (macOS)
code
#
# (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(111682);
  script_version("1.7");
  script_cvs_date("Date: 2019/11/04");

  script_cve_id("CVE-2018-8375", "CVE-2018-8382", "CVE-2018-8412");

  script_name(english:"Security Update for Microsoft Office (Auguest 2018) (macOS)");
  script_summary(english:"Checks the version of Microsoft Office.");

  script_set_attribute(attribute:"synopsis", value:
"An application installed on the remote macOS or Mac OS X host is
affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office 2016 application installed on the remote macOS
or Mac OS X host is missing a security update. It is, therefore,
affected by the following vulnerabilities:

  - An elevation of privilege vulnerability exists when the
    Microsoft AutoUpdate (MAU) application for Mac improperly
    validates updates before executing them. An attacker who
    successfully exploited the vulnerability who already has
    the ability to execute code on a system could elevate
    privileges. (CVE-2018-8412)

  - 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. Users whose accounts are
    configured to have fewer user rights on the system could
    be less impacted than users who operate with
    administrative user rights. (CVE-2018-8375)

  - An information disclosure vulnerability exists when
    Microsoft Excel improperly discloses the contents of its
    memory. An attacker who exploited the vulnerability could
    use the information to compromise the user's computer or
    data. (CVE-2018-8382)");
  # https://docs.microsoft.com/en-us/officeupdates/release-notes-office-for-mac
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?17ce16bb");
  # https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2018-8412
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d9d90788");
  # https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2018-8375
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5ea3bae2");
  # https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2018-8382
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1d985ef1");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for Microsoft Office 2016 for
Mac.");
  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: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-2018-8375");

  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:/o:apple:mac_os_x");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:office");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"MacOS X Local Security Checks");

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

  script_dependencies("macosx_office_installed.nbin");
  script_require_keys("Host/MacOSX/Version");
  script_require_ports("installed_sw/Microsoft Word", "installed_sw/Microsoft Excel", "installed_sw/Microsoft PowerPoint", "installed_sw/Microsoft OneNote", "installed_sw/Microsoft Outlook");

  exit(0);
}

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

os = get_kb_item("Host/MacOSX/Version");
if (!os) audit(AUDIT_OS_NOT, "Mac OS X");

apps = make_list(
  "Microsoft Word",
  "Microsoft Excel",
  "Microsoft PowerPoint",
  "Microsoft OneNote",
  "Microsoft Outlook"
);

report = "";

foreach app (apps)
{
  installs = get_installs(app_name:app);
  if (isnull(installs[1])) continue;
  foreach install (installs[1])
  {
    version = install['version'];
    app_label = app;
    fix = NULL;
    fix_disp = NULL;

    if (version =~ "^16\.")
    {
      app_label += " for Mac 2016";
      fix = '16.16.0';
      fix_disp = '16.16 (18081201)';
    }

    if (fix && ver_compare(ver:version, fix:fix, strict:FALSE) < 0)
    {
      report +=
        '\n  Product           : ' + app_label +
        '\n  Installed version : ' + version +
        '\n  Fixed version     : ' + fix_disp;

      fix_disp = '';
      if (os =~ "^Mac OS X 10\.[0-9](\.|$)")
        report += '\n  Note              : Update will require Mac OS X 10.10.0 or later.\n';
      else report += '\n';
    }
  }
}

# Report findings.
if (!empty(report))
  security_report_v4(severity:SECURITY_HOLE, port:0, extra:report);
else
  audit(AUDIT_HOST_NOT, "affected");