Actively exploited in the wild
Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability
Progress - Telerik UI for ASP.NET AJAX · Listed in the CISA KEV since 2021-11-03. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2019-18935
CriticalCVSS 9.8KEVSummary
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.)
Risk Assessment
High risk of remote code execution if encryption keys are known, potentially leading to full server compromise.
Recommendation
Update Progress Telerik UI for ASP.NET AJAX to version 2020.1.114 or later, which prevents exploitation by default.
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Original NVD description (English source)
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.)