CVE-2017-11357 in Telerik UI for ASP.NET AJAX
Summary
by MITRE
Progress Telerik UI for ASP.NET AJAX before R2 2017 SP2 does not properly restrict user input to RadAsyncUpload, which allows remote attackers to perform arbitrary file uploads or execute arbitrary code.
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2017-11357 affects Progress Telerik UI for ASP.NET AJAX versions prior to R2 2017 SP2, specifically within the RadAsyncUpload component. This flaw represents a critical security weakness that undermines the application's input validation mechanisms and creates opportunities for remote code execution through unauthorized file uploads. The vulnerability stems from insufficient sanitization of user-supplied data during the file upload process, allowing malicious actors to bypass security controls that should prevent the upload of potentially harmful files.
The technical implementation of this vulnerability lies in the improper handling of file name validation within the RadAsyncUpload control. Attackers can exploit this by crafting malicious file names that contain special characters or sequences designed to evade the component's built-in validation checks. The flaw operates at the input sanitization layer where the system fails to properly validate or sanitize file names before processing them, enabling attackers to inject malicious payloads that can be executed within the application context. This type of vulnerability is categorized under CWE-20, which describes improper input validation, and specifically relates to CWE-434, which addresses unrestricted file upload vulnerabilities.
The operational impact of this vulnerability extends beyond simple file upload capabilities, as it enables attackers to achieve remote code execution through the upload of malicious files such as web shells or executable binaries. When successful, this vulnerability allows threat actors to gain persistent access to the affected server, potentially leading to full system compromise. The attack vector requires only a remote connection to the vulnerable application, making it particularly dangerous for web applications that expose the Telerik UI components to untrusted users. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1190 for Exploit Public-Facing Application and T1059 for Command and Scripting Interpreter.
Organizations affected by this vulnerability should immediately apply the security patch released by Progress Software for the R2 2017 SP2 version of Telerik UI for ASP.NET AJAX. Additionally, implementing defensive measures such as restricting file type uploads, implementing strict file name validation, and deploying web application firewalls can help mitigate the risk. The recommended mitigation strategy involves not only patching the specific vulnerability but also establishing comprehensive input validation policies that enforce strict file extension checks and prevent the execution of uploaded files in the web root directory. Security monitoring should include detection of unusual file upload patterns and unauthorized access attempts to the RadAsyncUpload component, as these activities often precede successful exploitation attempts.