CVE-2017-9248 — Progress Telerik UI for ASP.NET AJAX and Sitefinity Cryptographic Weakness Vulne

Telerik.Web.UI.dll in Progress Telerik UI for ASP.NET AJAX before R2 2017 SP1 and Sitefinity before 10.0.6412.0 does not properly protect Telerik.Web.UI.DialogParametersEncryptionKey or the MachineKey, which makes it easier for remote attackers to defeat cryptographic protection

01What is this vulnerability?

Telerik.Web.UI.dll in Progress Telerik UI for ASP.NET AJAX before R2 2017 SP1 and Sitefinity before 10.0.6412.0 does not properly protect Telerik.Web.UI.DialogParametersEncryptionKey or the MachineKey, which makes it easier for remote attackers to defeat cryptographic protection mechanisms, leading to a MachineKey leak, arbitrary file uploads or downloads, XSS, or ASP.NET ViewState compromise.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2017-07-03T19:00:00.000Z
• Last modified: 2025-10-21T23:55:39.141Z
• Added to CISA KEV: 2021-11-03
• BOD 22-01 due: 2022-05-03

09References

• www.telerik.com — http://www.telerik.com/support/kb/aspnet-ajax/details/cryptographic-weakness
• www.exploit-db.com — https://www.exploit-db.com/exploits/43873/
• www.telerik.com — http://www.telerik.com/blogs/security-alert-for-telerik-ui-for-asp.net-ajax-and-…
• www.securityfocus.com — http://www.securityfocus.com/bid/99965