An issue was discovered in Progress Telerik UI for ASP.NET AJAX 2021.1.224. It allows unauthorized access to MicrosoftAjax.js through the Telerik.Web.UI.WebResource.axd file. This may allow the attacker to gain unauthorized access to the server and execute code. To exploit, one must use the parameter _TSM_HiddenField_ and inject a command at the end of the URI. NOTE: the vendor states that this is not a vulnerability. The request's output does not indicate that a "true" command was executed on the server, and the request's output does not leak any private source code or data from the server
Use CWE-862, Progress vendor hub and Telerik Ui For Asp.Net Ajax product page to widen CVE-2021-28141 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2017-11357, CVE-2019-19790 and CVE-2025-3600 for nearby disclosures in the same product family.