Vulnerabilities > CVE-2020-0759 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Microsoft Excel and Office 365 Proplus

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
NVD
Published: 2020-02-11
Updated: 2021-07-21

Summary

A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory, aka 'Microsoft Excel Remote Code Execution Vulnerability'.

Vulnerable Configurations

Part Description Count
Application
Microsoft
5

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.
  • 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.

Nessus

  • NASL familyMacOS X Local Security Checks
    NASL idMACOS_MS20_FEB_OFFICE.NASL
    descriptionThe Microsoft Office application installed on the remote macOS or Mac OS X host is missing a security update. It is, therefore, affected by a remote code execution vulnerability due to Microsoft Excel improperly handling objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. To exploit the vulnerability, an attacker has to entice the logged on user to click a link or open a specially crafted file to gain control of the system with the privileges of the logged on user.
    last seen2020-03-18
    modified2020-02-12
    plugin id133650
    published2020-02-12
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/133650
    titleSecurity Updates for Microsoft Office Products (February 2020) (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(133650);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/13");

  script_cve_id("CVE-2020-0759");

  script_name(english:"Security Updates for Microsoft Office Products (February 2020) (macOS)");

  script_set_attribute(attribute:"synopsis", value:
"An application installed on the remote macOS or Mac OS X host is 
  affected by a remote code execution vulnerability");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office application installed on the remote macOS or Mac OS X host is missing a security update. It is,
therefore, affected by a remote code execution vulnerability due to Microsoft Excel improperly handling objects in 
memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current
user. To exploit the vulnerability, an attacker has to entice the logged on user to click a link or open a specially 
crafted file to gain control of the system with the privileges of the logged on user.");
  # https://docs.microsoft.com/en-us/officeupdates/update-history-office-for-mac
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?43ed1b90");
  # https://docs.microsoft.com/en-us/officeupdates/release-notes-office-2016-mac
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?dae26676");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for Microsoft Office 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:N/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-2020-0759");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/01/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/12");

  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_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:excel");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:word");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:powerpoint");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:outlook");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020 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_or_exit('Host/MacOSX/Version');
apps = make_list(
  'Microsoft Word',
  'Microsoft Excel',
  'Microsoft PowerPoint',
  'Microsoft Outlook'
);
report = '';

#2016
min_ver_16 = '16';
fix_ver_16 = '16.16.19';
fix_disp_16 = '16.16.19 (20021000)';

#2019
min_ver_19 = '16.17.0';
fix_ver_19 = '16.34';
fix_disp_19 = '16.34 (20020900)';

foreach app (apps)
{
  installs = get_installs(app_name:app);
  if (isnull(installs[1]))
    continue;

  foreach install (installs[1])
  {
    version = install['version'];

    if (ver_compare(ver:version, minver:min_ver_19, fix:fix_ver_19, strict:FALSE) < 0)
    {
      app_label = app + ' for Mac 2019';
      report +=
        '\n\n  Product           : ' + app_label +
        '\n  Installed version : ' + version +
        '\n  Fixed version     : ' + fix_disp_19;
    }
    else if (ver_compare(ver:version, minver:min_ver_16, fix:fix_ver_16, strict:FALSE) < 0)
    {
      app_label = app + ' for Mac 2016';
      report +=
        '\n\n  Product           : ' + app_label +
        '\n  Installed version : ' + version +
        '\n  Fixed version     : ' + fix_disp_16;
    }
  }
}
if (empty(report))
  audit(AUDIT_HOST_NOT, 'affected');

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

security_report_v4(severity:SECURITY_HOLE, port:0, extra:report);
  • NASL familyWindows : Microsoft Bulletins
    NASL idSMB_NT_MS20_FEB_OFFICE.NASL
    descriptionThe Microsoft Office Products are 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-2020-0759) - A security feature bypass vulnerability exists in Microsoft Outlook software when it improperly handles the parsing of URI formats. The security feature bypass by itself does not allow arbitrary code execution. However, to successfully exploit the vulnerability, an attacker would have to use it in conjunction with another vulnerability, such as a remote code execution vulnerability, to take advantage of the security feature bypass vulnerability and run arbitrary code. (CVE-2020-0696) - An elevation of privilege vulnerability exists in Microsoft Office OLicenseHeartbeat task, where an attacker who successfully exploited this vulnerability could run this task as SYSTEM. (CVE-2020-0697)
    last seen2020-03-18
    modified2020-02-14
    plugin id133716
    published2020-02-14
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/133716
    titleSecurity Updates for Microsoft Office Products (February 2020)
    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(133716);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/14");

  script_cve_id("CVE-2020-0696", "CVE-2020-0697", "CVE-2020-0759");

  script_name(english:"Security Updates for Microsoft Office Products (February 2020)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft Office Products are affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office Products are 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-2020-0759)

  - A security feature bypass vulnerability exists in Microsoft Outlook software when it improperly handles
    the parsing of URI formats. The security feature bypass by itself does not allow arbitrary code execution.
    However, to successfully exploit the vulnerability, an attacker would have to use it in conjunction with
    another vulnerability, such as a remote code execution vulnerability, to take advantage of the security
    feature bypass vulnerability and run arbitrary code. (CVE-2020-0696)

  - An elevation of privilege vulnerability exists in Microsoft Office OLicenseHeartbeat task, where an
    attacker who successfully exploited this vulnerability could run this task as SYSTEM. (CVE-2020-0697)");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0696
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3c75b3fb");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0697
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?097c5011");
  # https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0759
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?002d43eb");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a security update to address this issue.

For Office 365, Office 2016 C2R, or Office 2019, ensure automatic updates are enabled or open any office app and 
manually perform an update.");
  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:N/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-2020-0759");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/02/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/14");

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

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

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("office_installed.nasl", "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');

bulletin = 'MS20-02';
get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');
get_kb_item_or_exit('SMB/Registry/Enumerated', exit_code:1);

vuln = FALSE;
port = kb_smb_transport();
office_vers = hotfix_check_office_version();

# Office 2016 / 2019 / C2R
if (office_vers['16.0'])
{
  office_sp = get_kb_item('SMB/Office/2016/SP');
  if (!isnull(office_sp) && office_sp == 0)
  {
    path = hotfix_get_officeprogramfilesdir(officever:'16.0');
    prod = 'Microsoft Office 2016';
    prod2019 = 'Microsoft Office 2019';
    mso_dll_path = hotfix_append_path(path:path, value:'Microsoft Office\\root\\Office16');
    c2r_path = mso_dll_path;
    if (
      hotfix_check_fversion(file:'graph.exe', version:'16.0.10730.20438', channel:'Deferred', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod) == HCF_OLDER ||
      hotfix_check_fversion(file:'graph.exe', version:'16.0.11328.20526', channel:'Deferred', channel_version:'1902', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod) == HCF_OLDER ||
      hotfix_check_fversion(file:'graph.exe', version:'16.0.11929.20606', channel:'First Release for Deferred', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod) == HCF_OLDER ||
      hotfix_check_fversion(file:'graph.exe', version:'16.0.12430.20264', channel:'Current', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod) == HCF_OLDER ||
      # 2019
      hotfix_check_fversion(file:'graph.exe', version:'16.0.12430.20264', channel:'2019 Retail', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod2019) == HCF_OLDER ||
      hotfix_check_fversion(file:'graph.exe', version:'16.0.10356.20006', channel:'2019 Volume', channel_product:'Office', path:c2r_path, bulletin:bulletin, product:prod2019) == HCF_OLDER
    )
    vuln = TRUE;
  }
}
if (vuln)
{
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_hole();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, 'affected');
}
  • NASL familyWindows : Microsoft Bulletins
    NASL idSMB_NT_MS20_FEB_EXCEL.NASL
    descriptionThe Microsoft Excel Products are missing a security update. It is, therefore, affected by the following vulnerability : - 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.
    last seen2020-04-18
    modified2020-02-11
    plugin id133616
    published2020-02-11
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/133616
    titleSecurity Updates for Microsoft Excel Products (February 2020)

Talos

idTALOS-2019-0968
last seen2020-02-15
published2020-02-11
reporterTalos Intelligence
sourcehttp://www.talosintelligence.com/vulnerability_reports/TALOS-2019-0968
titleMicrosoft Office Excel Ordinal43 code execution vulnerability

References