Progress Telerik UI - RCE (CVE-2019-18935)

CVE-2019-18935 is a critical vulnerability in Progress Telerik UI for ASP.NET AJAX that enables remote code execution through a flawed deserialization process in the RadAsyncUpload functionality, especially when encryption keys are exposed or known.

CrowdSec has been tracking this vulnerability and its exploits since 5th of April 2023.

Based on data from the CrowdSec network, nearly all observed exploitation of CVE-2019-18935 is fully opportunistic, with attackers indiscriminately scanning the entire internet. These attacks are automated and lack any form of target selection or reconnaissance. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2019-18935 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2019-18935 is currently experiencing high visibility and active exploitation across the internet.

Observed exploitation frequently involves requests crafted to abuse the RadAsyncUpload feature, leveraging the underlying deserialization flaw for code execution.