After covering the context of those two CVEs, we’ll dive deeper into the insecure deserialization vulnerability to learn if it affects your system, how the exploit works, and how you can patch systems against this vulnerability. If the application using RadAsyncUpload does not require authentication, then you can usually find the UI version buried somewhere in the HTML source of the application's home page. We have provided these links to other web sites because they Telerik UI for ASP.NET AJAX is a widely used suite of UI components for web applications. 8240 S. Kyrene Rd.Suite A113 Tempe, AZ85284 United States. If this encryption key was not changed from its default value of PrivateKeyForEncryptionOfRadAsyncUploadConfiguration, an attacker could use that key to craft a file upload request to /Telerik.Web.Ui.WebResource.axd?type=rau with a custom encrypted rauPostData POST parameter. Statement | NIST Privacy Program | No Until R2 2017 SP1 (v2017.2.621), RadAsyncUpload's AsyncUploadHandler was configured with a hard-coded key that was used to encrypt form data in file upload requests. Even though the unrestricted file upload vulnerability had been extensively discussed since its discovery in 2017, Markus Wulftange took a closer look at the way RadAsyncUpload processed the rauPostData parameter in file upload requests in early 2019. the new file to the old one. View Analysis Description So, "managed" code is written to run exclusively under the CLR, a layer that wraps native compiled code to prevent some common problems (e.g., buffer overflows) and abstract away some platform-specific implementation details to make code more portable. Fear Act Policy, Disclaimer Webmaster | Contact Us The version of Telerik UI for ASP.NET AJAX installed on the remote Windows host is affected by multiple vulnerabilities in Telerik.Web.UI.dll. Exploitation can result in remote code execution. (In 2019.3.1023 but not earlier versions, a non-default setting can prevent exploitation.). RadAsyncUpload component in not used in the web app, is the app still vulnerable to the known vulnerabilities in the RadAsyncUpload? Validated Tools SCAP USGCB, US-CERT Security Operations Center Email: Phone:            PROBLEM Security vulnerabilities CVE-2014-2217 and CVE-2017-11317: weak encryption has been used in old versions of Telerik.Web.UI to encrypt data used by RadAsyncUpload. They are present in one of the assemblies distributed with Sitefinity CMS - Telerik.Web.UI.dll. (As of 2020.1.114, a default setting prevents the exploit. | Daily cybersecurity news articles on the latest breaches, hackers, exploits and cyber threats. Modify the configuration to allow file uploading anywhere they like on the target web server. Choose one of the static resources there and examine its Last-Modified date in the HTTP response header; that date should roughly match the release date of the software. Denotes Vulnerable Software Before attempting to exploit Telerik UI for ASP.NET AJAX, confirm first that the file upload handler is registered: Additionally, you’ll need to confirm that the web application is using a vulnerable version of this software. Vulnerability Assessments. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. It is awaiting reanalysis which may result in further changes to the information provided. Create a bare C# class in empty.cs to constitute the managed portion of your mixed mode assembly: Then, in a Windows environment with Visual Studio installed, open a command prompt and run build_dll.bat sleep.c: build_dll.bat. 800-53 Controls SCAP Telerik.Web.UI.RadAsyncUpload.Handling.Arbitrary.File.Upload Description This indicates an attack attempt to exploit an Arbitrary File Upload vulnerability in Telerik UI for ASP.NET AJAX components. This module exploits the.NET deserialization vulnerability within the RadAsyncUpload (RAU) component of Telerik UI ASP.NET AJAX that is identified as CVE-2019-18935. Notice | Accessibility After using the aforementioned unrestricted file upload vulnerability to upload a malicious mixed mode assembly DLL, an attacker may follow up with a second request to force JavaScriptSerializer to deserialize an object of type System.Configuration.Install.AssemblyInstaller. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. I suspect that this is because the target environment did not have the Microsoft Visual C++ Redistributable installed. 'Exploit for CVE-2019-18935, a .NET deserialization vulnerability in Telerik UI for ASP.NET AJAX. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. It is the most fundamental unit of deployment for a .NET application, and can be implemented as an EXE or DLL file. This means that an assembly "sleep_123.dll" may cause the application to sleep the first time that DLL is loaded through deserialization, but it certainly won't successfully load again; you'll need to rerun build_dll.bat to generate a new assembly for each exploit attempt on the same server. Discussion Lists, NIST CIL, in turn, is compiled into native code by a just-in-time compiler within the CLR. Telerik. For more details, please refer to Implications of Loading .NET Assemblies and Friday the 13th JSON Attacks. Explore the powerful features and capabilities by browsing the hundreds of online examples on the Telerik demo site. If an attacker specified an arbitrary value for the TempTargetFolder variable within the encrypted rauPostData POST parameter, it would effectively allow file uploads to any directory where the web server had write permissions. Integrity Summary | NIST Attackers are actively scanning for and attempting to exploit the vulnerability discovered in a number of Telerik products November 2019, which was the subject of a previous ACSC advisory. [0-9]*)+ (and make sure you check the "Regex" box). The Telerik security advisory tells you what you need to know, but we’ll repeat the most important parts here: This write-up has demonstrated how an attacker can chain exploits for unrestricted file upload (CVE-2017-11317) and insecure deserialization (CVE-2019-18935) vulnerabilities to execute arbitrary code on a remote machine. Without being able to remotely determine the architecture of the web server's underlying host, you may need to attempt to trigger this vulnerability with both the 32- and 64-bit DLL versions until you find one that works. The issues were fixed in Telerik's public assemblies starting from 2017.2.711. By selecting these links, you will be leaving NIST webspace. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. | FOIA | When deserialized along with an attacker-supplied Path property pointing to the uploaded DLL, this will cause the application to load the DLL into its current domain. For further reading, check out this article about injecting .NET assemblies which provides a useful .NET primer, and a related article on mixed assemblies. This is a potential security issue, you are being redirected to NIST does Disclaimer | Scientific Rapid7's VulnDB is curated repository of vetted computer software exploits and exploitable vulnerabilities. The location of the version string isn't consistent, though, so the best method of locating it is to use Burp to search for the regular expression 20[0-9]{2}(\. A gadget is a class within the executing scope of the application that, as a side effect of being instantiated and modified via setters or field assignment, has special properties that make it useful during deserialization. Now that Telerik has released a patch and security advisory for this vulnerability, affected users should do their part by updating and securely configuring their applications. Environmental Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. We use rev_shell.c below, a program that launches a reverse shell as a thread when the DLL is loaded; the threaded nature of this program prevents the shell process from blocking the web application's user interface while running: rev_shell.c. In order to do so the module must upload a mixed mode.NET assembly DLL which is then loaded through the deserialization flaw. A simple program, sleep.c, will do just that. There may be other web may have information that would be of interest to you. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. # One extra input is required for the page to process the request. Calculator CVSS CISA, Privacy No The attack is also targeting old Telerik UI vulnerabilities that have already been patched. If attackers were able to break the encryption protecting the configuration object in the facts presented on these sites. Exploitation can result in remote code execution. UPDATE: Caleb presented on this topic at 2020 DerpCon, which you can watch below. Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. As such, computer code written using .NET Framework is called "managed code.". Patching instructions are included at the end of this post. Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a.NET deserialization vulnerability in the RadAsyncUpload function. - Your app will be safe from the known vulnerabiltieis if the Telerik.Web.UI.dll assembly is released before Q1 2010 (version 2010.1.309) or … If this type is controlled by an attacker, this can lead to a dangerous scenario where the attacker may specify the type to be a gadget. Let's break these down a bit, starting with a useful description from Wikipedia about how programs execute when developed in .NET: Programs written for .NET Framework execute in a software environment (in contrast to a hardware environment) named the Common Language Runtime (CLR). 1-888-282-0870, Sponsored by The attack often uses the known vulnerabilities CVE-2017-11317 and CVE-2019-18935 They are already fixed, when they were found, and Progress notified customers with instructions and mitigation steps. As long as the mixed mode assembly DLL is of the same architecture as the loading process, its entry-point function DLLMain() will be called when the DLL is loaded. Today, we’ll be looking at a vulnerability we found in the Telerik UI for ASP.NET AJAX, which has been assigned CVE-2014-2217. Exploitation can result in remote code execution. ), Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. Rather than submitting the usual expected Telerik.Web.UI.AsyncUploadConfiguration type within rauPostData, an attacker can submit a file upload POST request specifying the type as an RCE gadget instead. As we continue to identify and understand this class of vulnerabilities, it’s important that vendors and users employ timely communication to combat the risk posed by vulnerable software. The following exploit script leverages the core RadAsyncUpload encryption logic provided by Paul Taylor's to craft an encrypted rauPostData POST parameter; this enables access to the vulnerable AsyncUploadHandler class through which we can upload files and deserialize arbitrary object types. Telerik Web UI RadAsyncUpload Deserialization Description The Telerik UI component for ASP.NET AJAX (versions 2019.3.917 and older) are deserializing JSON objects in an insecure manner that results in arbitrary remote code execution on the software's underlying host. referenced, or not, from this page. The control addresses the limitation to perform file uploads with plain post backs only, and supports web farm scenarios, as well as internal validation, using its http handler for this purpose. You can also accomplish this with cURL: If that doesn't work, you can alternatively search for the string