Vulnerabilities > CVE-2016-0051 - Permissions, Privileges, and Access Controls vulnerability in Microsoft products

047910
CVSS 7.2 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
local
low complexity
microsoft
CWE-264
nessus
exploit available
metasploit

Summary

The WebDAV client in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 allows local users to gain privileges via a crafted application, aka "WebDAV Elevation of Privilege Vulnerability."

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.

Exploit-Db

  • descriptionWindows 7 - WebDAV Privilege Escalation Exploit (MS16-016). CVE-2016-0051. Local exploit for windows platform
    fileexploits/windows/local/39788.txt
    idEDB-ID:39788
    last seen2016-05-09
    modified2016-05-09
    platformwindows
    port
    published2016-05-09
    reporterhex0r
    sourcehttps://www.exploit-db.com/download/39788/
    titleWindows 7 - WebDAV Privilege Escalation Exploit MS16-016 #2
    typelocal
  • descriptionMicrosoft Windows WebDAV BSoD PoC (MS-016). CVE-2016-0051. Dos exploit for windows platform
    fileexploits/windows_x86/local/39432.c
    idEDB-ID:39432
    last seen2016-02-11
    modified2016-02-10
    platformwindows_x86
    port
    published2016-02-10
    reporterkoczkatamas
    sourcehttps://www.exploit-db.com/download/39432/
    titleMicrosoft Windows WebDAV - BSoD PoC MS16-016
    typelocal
  • descriptionMS16-016 mrxdav.sys WebDav Local Privilege Escalation. CVE-2016-0051. Local exploit for windows platform
    fileexploits/windows/local/40085.rb
    idEDB-ID:40085
    last seen2016-07-11
    modified2016-07-11
    platformwindows
    port
    published2016-07-11
    reportermetasploit
    sourcehttps://www.exploit-db.com/download/40085/
    titleMS16-016 mrxdav.sys WebDav Local Privilege Escalation
    typelocal

Metasploit

descriptionThis module exploits the vulnerability in mrxdav.sys described by MS16-016. The module will spawn a process on the target system and elevate its privileges to NT AUTHORITY\SYSTEM before executing the specified payload within the context of the elevated process.
idMSF:EXPLOIT/WINDOWS/LOCAL/MS16_016_WEBDAV
last seen2020-05-31
modified2020-01-15
published2016-07-06
referenceshttps://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0051
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/exploits/windows/local/ms16_016_webdav.rb
titleMS16-016 mrxdav.sys WebDav Local Privilege Escalation

Msbulletin

bulletin_idMS16-016
bulletin_url
date2016-02-09T00:00:00
impactElevation of Privilege
knowledgebase_id3136041
knowledgebase_url
severityImportant
titleSecurity Update for WebDAV to Address Elevation of Privilege

Nessus

NASL familyWindows : Microsoft Bulletins
NASL idSMB_NT_MS16-016.NASL
descriptionThe remote Windows host is missing a security update. It is, therefore, affected by a flaw in the Microsoft Web Distributed Authoring and Versioning (WebDAV) client due to improper validation of user-supplied input. A local attacker can exploit this, via a specially crafted application, to execute arbitrary code with elevated privileges.
last seen2020-06-01
modified2020-06-02
plugin id88648
published2016-02-09
reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/88648
titleMS16-016: Security Update for WebDAV to Address Elevation of Privilege (3136041)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(88648);
  script_version("1.15");
  script_cvs_date("Date: 2019/11/20");

  script_cve_id("CVE-2016-0051");
  script_bugtraq_id(82682);
  script_xref(name:"MSFT", value:"MS16-016");
  script_xref(name:"MSKB", value:"3135173");
  script_xref(name:"MSKB", value:"3124280");
  script_xref(name:"MSKB", value:"3135174");
  script_xref(name:"IAVA", value:"2016-A-0049");

  script_name(english:"MS16-016: Security Update for WebDAV to Address Elevation of Privilege (3136041)");
  script_summary(english:"Checks the version of mrxdav.sys");

  script_set_attribute(attribute:"synopsis", value:
"The remote host is affected by an elevation of privilege
vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote Windows host is missing a security update. It is,
therefore, affected by a flaw in the Microsoft Web Distributed
Authoring and Versioning (WebDAV) client due to improper validation of
user-supplied input. A local attacker can exploit this, via a
specially crafted application, to execute arbitrary code with elevated
privileges.");
  script_set_attribute(attribute:"see_also", value:"https://docs.microsoft.com/en-us/security-updates/SecurityBulletins/2016/ms16-016");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for Windows Vista, 2008, 7,
2008 R2, 2012, 8.1, RT 8.1, 2012 R2, and 10.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/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:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-0051");

  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:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'MS16-016 mrxdav.sys WebDav Local Privilege Escalation');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/02/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/02/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/02/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("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_hotfixes_fcheck.inc");
include("smb_hotfixes.inc");
include("smb_func.inc");
include("misc_func.inc");

get_kb_item_or_exit("SMB/MS_Bulletin_Checks/Possible");

bulletin = 'MS16-016';
kbs = make_list('3135173', '3124280', '3135174');

if (get_kb_item("Host/patch_management_checks")) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_HOLE);

get_kb_item_or_exit("SMB/Registry/Enumerated");
get_kb_item_or_exit("SMB/WindowsVersion", exit_code:1);
productname = get_kb_item_or_exit("SMB/ProductName", exit_code:1);

if (hotfix_check_sp_range(vista:'2', win7:'1', win8:'0', win81:'0', win10:'0') <= 0) audit(AUDIT_OS_SP_NOT_VULN);
if ("Windows 8" >< productname && "8.1" >!< productname) audit(AUDIT_OS_SP_NOT_VULN);

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

share = hotfix_get_systemdrive(as_share:TRUE, exit_on_fail:TRUE);
if (!is_accessible_share(share:share)) audit(AUDIT_SHARE_FAIL, share);


if (
  # Windows 8.1 / Windows Server 2012 R2
  hotfix_is_vulnerable(os:"6.3", sp:0, file:"mrxdav.sys", version:"6.3.9600.18189", min_version:"6.3.9600.16000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||

  # Windows Server 2012
  hotfix_is_vulnerable(os:"6.2", sp:0, file:"mrxdav.sys", version:"6.2.9200.21738", min_version:"6.2.9200.20000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||
  hotfix_is_vulnerable(os:"6.2", sp:0, file:"mrxdav.sys", version:"6.2.9200.17619", min_version:"6.2.9200.16000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||

  # Windows 7 / Server 2008 R2
  hotfix_is_vulnerable(os:"6.1", sp:1, file:"mrxdav.sys", version:"6.1.7601.23317", min_version:"6.1.7601.22000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||
  hotfix_is_vulnerable(os:"6.1", sp:1, file:"mrxdav.sys", version:"6.1.7601.19113", min_version:"6.1.7600.16000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||

  # Vista / Windows Server 2008
  hotfix_is_vulnerable(os:"6.0", sp:2, file:"mrxdav.sys", version:"6.0.6002.23886", min_version:"6.0.6002.23000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280") ||
  hotfix_is_vulnerable(os:"6.0", sp:2, file:"mrxdav.sys", version:"6.0.6002.19576", min_version:"6.0.6002.18000", dir:"\system32\drivers", bulletin:bulletin, kb:"3124280")
)
  vuln++;
if (
  # 10 RTM
  hotfix_is_vulnerable(os:"10", sp:0, file:"mrxdav.sys", version:"10.0.10240.16683", dir:"\system32\drivers", bulletin:bulletin, kb:"3135174") ||
  # 10 threshold 2 (aka 1511)
  hotfix_is_vulnerable(os:"10", sp:0, file:"mrxdav.sys", version:"10.0.10586.103", min_version:"10.0.10586.0", dir:"\system32\drivers", bulletin:bulletin, kb:"3135173")
)
  vuln++;

if (vuln)
{
  set_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');
}

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