Vulnerabilities > CVE-2014-4073 - Permissions, Privileges, and Access Controls vulnerability in Microsoft .Net Framework
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
COMPLETE Integrity impact
COMPLETE Availability impact
COMPLETE Summary
Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 processes unverified data during interaction with the ClickOnce installer, which allows remote attackers to gain privileges via vectors involving Internet Explorer, aka ".NET ClickOnce Elevation of Privilege Vulnerability."
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 7 |
Common Weakness Enumeration (CWE)
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
| description | Windows 10 Realtek Audio Driver 6.0.1.7898 - Dolby Audio X2 Service Privilege Escalation. CVE-2017-7293. Local exploit for Windows platform |
| file | exploits/windows/local/41933.txt |
| id | EDB-ID:41933 |
| last seen | 2017-04-25 |
| modified | 2017-04-25 |
| platform | windows |
| port | |
| published | 2017-04-25 |
| reporter | Exploit-DB |
| source | https://www.exploit-db.com/download/41933/ |
| title | Windows 10 Realtek Audio Driver 6.0.1.7898 - Dolby Audio X2 Service Privilege Escalation |
| type | local |
Msbulletin
| bulletin_id | MS14-057 |
| bulletin_url | |
| date | 2014-10-14T00:00:00 |
| impact | Remote Code Execution |
| knowledgebase_id | 3000414 |
| knowledgebase_url | |
| severity | Critical |
| title | Vulnerabilities in .NET Framework Could Allow Remote Code Execution |
Nessus
| NASL family | Windows : Microsoft Bulletins |
| NASL id | SMB_NT_MS14-057.NASL |
| description | The remote Windows host has a version of the Microsoft .NET Framework that is affected by a vulnerability that allows a remote attacker to to execute code remotely. |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 78432 |
| published | 2014-10-15 |
| reporter | This script is Copyright (C) 2014-2018 Tenable Network Security, Inc. |
| source | https://www.tenable.com/plugins/nessus/78432 |
| title | MS14-057: Vulnerabilities in .NET Framework Could Allow Remote Code Execution (3000414) |
| code | |
Seebug
bulletinFamily exploit description Windows: Dolby Audio X2 Service Elevation of Privilege Platform: Windows 10 + Realtek Audio Driver version 6.0.1.7898 (on a Lenovo P50). Version of the service binary 0.7.2.61 built on 7/18/2016. Class: Elevation of Privilege #### Summary: The DAX2API service installed as part of the Realtek Audio Driver on Windows 10 is vulnerable to a privilege escalation vulnerability which allows a normal user to get arbitrary system privileges. #### Description: The DAX2API service is a DCOM service written in .NET running at system privileges. The use of .NET for DCOM is inherently unsafe and should not be used. There’s public exploit code to elevate privileges on arbitrary services available at https://github.com/tyranid/ExploitDotNetDCOM. Microsoft recommends moving from using DCOM to WCF for .NET services of different privilege levels. See https://blogs.technet.microsoft.com/srd/2014/10/14/more-details-about-cve-2014-4073-elevation-of-privilege-vulnerability/ for more information. Proof of Concept: To demonstrate the vulnerability download the project https://github.com/tyranid/ExploitDotNetDCOM and compile using Visual Studio. The executable to use is ExploitDotNetDCOMSerialization.exe. 1) From a command prompt run the command “ExploitDotNetDCOMSerialization.exe 6A28A945-790C-4B68-B0F4-34EEB1626EE3 notepad” 2) Check the currently running processes for the privileged copy of notepad, Expected Result: No privilege escalation occurs. Observed Result: An instance of notepad is running at system privileges. id SSV:93058 last seen 2017-11-19 modified 2017-04-27 published 2017-04-27 reporter Root title Windows: Dolby Audio X2 Service EoP (CVE-2017-7293) bulletinFamily exploit description Windows: ManagementObject Arbitrary .NET Serialization RCE Platform: .NET 4.6, Powershell 4. Tested between Server 2016 and Windows 10 Anniversary Edition Class: Remote Code Execution #### Summary: Accessing a compromised WMI server over DCOM using System.Management classes or the Powershell Get-WmiObject Cmdlet can lead to the server running arbitrary code on the calling machine leading to RCE. #### Description: The dangers of using .NET for DCOM are well know, the SRD blog made a post (https://blogs.technet.microsoft.com/srd/2014/10/14/more-details-about-cve-2014-4073-elevation-of-privilege-vulnerability/) which explicitly said it shouldn’t be used between trust boundaries. Presumably people took this to mean implementing servers, but it’s also a risk if a .NET DCOM client connects to an untrusted endpoint. This is due to the IManagedObject interface which will automatically force a client to deserialize an untrusted BinaryFormatter stream which is known bad. One common use of DCOM in the .NET framework is for WMI access. The old classes in the System.Management namespace are still accessible (even though technically supersceded by Cim classes) and in powershell they act as the backend for Get-WmiObject and family. Through inspection it’s clear that a number of places the client querys for IManagedObject (for example on the IWbemServices object returned from IWbemLevel1Login::NTLMLogin method) and would be vulnerable. If this interface is being queried it means that a .NET client is trying to create an RCW and will try and create a local copy of a remote serializable object. Therefore in corporate scenarios where some central system is using WMI over DCOM for management and analysis of running systems (and the management code is using the old .NET/PS classes to do the calls) a compromised machine which replaces the WMI service with its own malicious one could get arbitrary code execution on the monitoring machine. As this is typically going to be a higher privileged account (due to the requirements of DCOM access) it probably makes it more serious. Looking at the network traffic the initial CreateInstance call on the remote activator is only using CONNECT level authentication. This means that it might also be possible to MITM (or Man-At-The-Side) a .NET WMI client and send it back a malicious COM objref to get it to communicate with the attacker's server. Of course ideally no one would do this, or use the old style .NET and PS commands. But I’m sure there are networks out there which do so. Proof of Concept: I’ve provided a PoC as a C# project. You’ll need to also set up some machines to test this out. I’ve tested it in a simple environment of a Server 2016 server acting as a DC and a Windows 10 client. The serialized stream is tailored specifically for 4.6, I don’t know if it works anywhere else. 1) Compile the C# project and copy the binary to c:\service\FakeWmiServer.exe on the Client machine. 2) Run the following commands in admin Powershell on the client machine to configure the WMI service and add the server executable to the firewall. New-NetFirewallRule -DisplayName FAKEWMI -Enabled True -Profile Any -Direction Inbound -Program C:\service\FakeWMIService.exe -Protocol Tcp -LocalPort Any -RemotePort Any -LocalAddress Any -RemoteAddress Any New-NetFirewallRule -DisplayName FAKEWMI -Enabled True -Profile Any -Direction Outbound -Program C:\service\FakeWMIService.exe -Protocol Tcp -LocalPort Any -RemotePort Any -LocalAddress Any -RemoteAddress Any sc.exe config winmgmt binPath= c:\service\FakeWMIService.exe type= own Restart-Service winmgmt -Force 3) On the server start powershell. 4) On the server execute the PS command “Get-WmiObject -Class Win32_Process -ComputerName hostname” replacing hostname with the address of the client. Expected Result: WMI connection fails. Observed Result: A copy of CMD and Notepad is executed on the server in the context of the calling user. id SSV:92967 last seen 2017-11-19 modified 2017-04-19 published 2017-04-19 reporter Root title Windows: ManagementObject Arbitrary .NET Serialization RCE（CVE-2017-0160）
References
- http://blogs.technet.com/b/srd/archive/2014/10/14/more-details-about-cve-2014-4073-elevation-of-privilege-vulnerability.aspx
- http://secunia.com/advisories/60969
- http://www.securityfocus.com/bid/70313
- http://www.securitytracker.com/id/1031021
- https://docs.microsoft.com/en-us/security-updates/securitybulletins/2014/ms14-057