Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. Exploitation can result in remote code execution. (As of 2020.1.114, a default setting prevents the exploit. In 2019.3.1023, but not earlier versions, a non-default setting can prevent exploitation.)

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.