Vulnerabilities > CVE-2014-6324 - Permissions, Privileges, and Access Controls vulnerability in Microsoft products

047910
CVSS 9.0 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
low complexity
microsoft
CWE-264
critical
nessus
exploit available
metasploit

Summary

The Kerberos Key Distribution Center (KDC) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold and R2 allows remote authenticated domain users to obtain domain administrator privileges via a forged signature in a ticket, as exploited in the wild in November 2014, aka "Kerberos Checksum 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

  • descriptionMS14-068. CVE-2014-6324. Remote exploit for windows platform
    idEDB-ID:35474
    last seen2016-02-04
    modified2014-12-05
    published2014-12-05
    reporterSylvain Monne
    sourcehttps://www.exploit-db.com/download/35474/
    titleWindows Kerberos - Elevation of Privilege MS14-068
  • descriptionHackBack - A DIY Guide. Papers exploit for Multiple platform
    idEDB-ID:41915
    last seen2017-04-25
    modified2016-04-17
    published2016-04-17
    reporterExploit-DB
    sourcehttps://www.exploit-db.com/download/41915/
    titleHackBack - A DIY Guide

Metasploit

descriptionThis module exploits a vulnerability in the Microsoft Kerberos implementation. The problem exists in the verification of the Privilege Attribute Certificate (PAC) from a Kerberos TGS request, where a domain user may forge a PAC with arbitrary privileges, including Domain Administrator. This module requests a TGT ticket with a forged PAC and exports it to a MIT Kerberos Credential Cache file. It can be loaded on Windows systems with the Mimikatz help. It has been tested successfully on Windows 2008.
idMSF:AUXILIARY/ADMIN/KERBEROS/MS14_068_KERBEROS_CHECKSUM
last seen2020-06-05
modified2020-02-18
published2014-12-22
references
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/admin/kerberos/ms14_068_kerberos_checksum.rb
titleMS14-068 Microsoft Kerberos Checksum Validation Vulnerability

Msbulletin

bulletin_idMS14-068
bulletin_url
date2014-11-11T00:00:00
impactElevation of Privilege
knowledgebase_id3011780
knowledgebase_url
severityCritical
titleVulnerability in Kerberos Could Allow Elevation of Privilege

Nessus

NASL familyWindows : Microsoft Bulletins
NASL idSMB_NT_MS14-068.NASL
descriptionThe remote Windows host is affected by a privilege escalation vulnerability due to the Kerberos Key Distribution Center (KDC) implementation not properly validating signatures. A remote attacker can exploit this vulnerability to elevate an unprivileged domain user account to a domain administrator account. ESKIMOROLL is one of multiple Equation Group vulnerabilities and exploits disclosed on 2017/04/14 by a group known as the Shadow Brokers.
last seen2020-06-01
modified2020-06-02
plugin id79311
published2014-11-18
reporterThis script is Copyright (C) 2014-2018 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/79311
titleMS14-068: Vulnerability in Kerberos Could Allow Elevation of Privilege (3011780) (ESKIMOROLL)

Seebug

bulletinFamilyexploit
description### Description `MS14-068` is a Windows vulnerability in the Key Distribution Center (KDC) service. It allows an authenticated user to insert an arbitrary PAC (a structure that represent all user rights) in its Kerberos ticket (the TGT). > https://technet.microsoft.com/library/security/ms14-068.aspx In Windows domains, it permits privilege escalation (usually `standard user` to `domain/enterprise admin`) ### Technical The vulnerability is in the Key Distribution Center (KDC - `kdcsvc.dll`) of domain controllers. An user can obtain tickets by presenting a Kerberos TGT with an altered PAC. Normally the KDC service detects a PAC alteration by verifying its signature (each KDC knows the secret symmetric key to check it) **The vulnerability:** KDC service allows algorithms without keys (like `MD4`, `MD5`, `SHA1` or `CRC32`) to be used. It means that any user can forge a PAC without knowing any secret key, and ask the KDC to include it in a ticket. #### Workflow 1. (AS-REQ) User authenticates to a KDC, asking a TGT without a PAC. 2. (PAC TIME) User creates a PAC with arbitrary data and seal it with an algorithm without keys (here, `MD5`). 3. (TGS-REQ) From its TGT, user asks a TGS for service `krbtgt` (TGT-like) with its fake PAC included. 4. (TGS-REQ) From its TGS, user asks another TGS for service `krbtgt` (TGT-like) - _if vulnerable, fake PAC will be really signed by KDC here!_ 5. (KRB-CRED) From the final TGS, ticket is converted as KRB-CRED structure (to be saved on disk or injected in `LSA`) Step 4. seems to be optional, but is necessary to use a TGT with a PAC well signed with a domain controller not vulnerable (load balancing). ## Arguments #### Standard * `/domain` - the fully qualified domain name of the target (ex: `lab.local`) * `/user` - the username you want to use as authenticated user (any account allowed to logon is OK, ex: `utilisateur`) Then you can choose between: * `/password` - the password of the user's account * `/key` - the derived key of the user's account, it can be `RC4_HMAC_NT` (`NTLM`), `AES128_CTS_HMAC_SHA1_96` or `AES256_CTS_HMAC_SHA1_96` By default, `/key` and `/password` will be used with `RC4_HMAC_NT` algorithm, but you can specify `/aes128` (`AES128_CTS_HMAC_SHA1_96`) or `/aes256` (`AES256_CTS_HMAC_SHA1_96`) Final usage is between: * `/ticket` - _optional_ - file name used to write ticket(s) on the disk - default is: `tgt.kirbi` * `/ptt` - _optional_ - `Pass The Ticket`: no ticket will be written, first good ticket is injected in `LSA` (NT6 is needed) #### Automatically recovered If not provided, these arguments can be recovered remotely by RPC/CLDAP, in this case: `/password` is mandatory and `/key` is not permitted. * `/sid` - _optional_ - the **domain**'s SID (ex: `S-1-5-21-1644491937-412668190-839522115`) * `/rid` - _optional_ - the **user**'s relative ID (ex: `1105`) * `/kdc` - _optional_ - the DC you want to use for all queries (ex: `dc.lab.local`), if not provided, the program will select one automatically, then: * test *all* KDC in the domain * when saving ticket in file: save each successful tickets in separate files, named like `%dcshortname%.%filename%.kirbi` * when `Pass The Ticket`: inject the first successful ticket in `LSA` then break the loop * print a little repport at the end with the number of vulnerable servers vs the total. #### Tuning * `/groups` - _optional_ - relatives id of groups which the user will belong (first is primary group, comma separator) - default is: `513,512,520,518,519` for the well-known Administrator's groups. * `/sids` - _optional_ - externals SID (externals to the domain) to add. * an interesting SID is `S-1-5-21-root forest-519` (Enterprise Admins) # Errors * `KDC_ERR_WRONG_REALM (68)`: bad domain name * `KDC_ERR_PREAUTH_FAILED (24)`: bad password or key * `KDC_ERR_ETYPE_NOSUPP (14)`: you try to make AES on 2003 domain functional level (or algorithm is not allowed) * `KDC_ERR_SUMTYPE_NOSUPP (15)`: * NT6 target: `KB3011780` patch or > is installed * `KRB_ERR_GENERIC (60)`: * NT5 target: `KB3011780` patch or > is installed * NT6 target: 2012 server or > is not vulnerable to this program Others errors: * `ERROR stringToKey ; LocacteCSystem: 80080341`: you try to use AES on a NT5 client (RC4 support only), please use a NT6 machine. * `ERROR [...] ; LsaCallAuthenticationPackage KerbSubmitTicketMessage : c000000d`: you try to make `Pass The Ticket` on a NT5 client. Like with `mimikatz`, it’s a NT6 only feature. ### Remarks * All DC without `KB3011780` patch or >, are vulnerable (like all Windows 2000)
idSSV:92950
last seen2017-11-19
modified2017-04-15
published2017-04-15
reporterRoot
sourcehttps://www.seebug.org/vuldb/ssvid-92950
titleESKIMOROLL-ms14-068 Windows vulnerability in the Key Distribution Center (KDC) service (CVE-2014-6324)

The Hacker News

idTHN:CD55D97C4B7F0F15409E50C509B347D3
last seen2018-01-27
modified2014-11-19
published2014-11-18
reporterSwati Khandelwal
sourcehttps://thehackernews.com/2014/11/microsoft-releases-emergency-out-of.html
titleMicrosoft Releases Emergency Out-of-Band Patch for Kerberos Bug MS14-068