Progress Telerik UI for ASP.NET AJAX and Sitefinity Cryptographic Weakness Vulnerability

CRITICAL 9.8EXPLOITED (CISA KEV)CVE-2017-9248 · Published 03/07/2017 · updated 17/06/2026

Progress Telerik UI for ASP.NET AJAX and Sitefinity Cryptographic Weakness Vulnerability. Actively exploited: CISA added this vulnerability to its Known Exploited Vulnerabilities catalog on 03/11/2021. Patch affected systems as an emergency.

Package	Affected versions	Patched versions
sitefinity progress	`< 10.0.6412.0`	`10.0.6412.0`
ui for asp.net ajax telerik	`≤ 2017.2.503`	No fix yet

Description

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.

References

securityfocus.com/bid/99965 · Broken Link
telerik.com/blogs/security-alert-for-telerik-ui-for-asp.net-ajax-and-progress-sitefinity · Vendor Advisory
telerik.com/support/kb/aspnet-ajax/details/cryptographic-weakness · Mitigation
exploit-db.com/exploits/43873 · Exploit
cisa.gov/known-exploited-vulnerabilities-catalog · US Government Resource
CISA KEV · CVE-2017-9248

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