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

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Progress
Product
ASP.NET AJAX and Sitefinity
EPSS
99.6th percentile (score 0.894, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2017-9248

CISA short description

Progress Telerik UI for ASP.NET AJAX and Sitefinity have a cryptographic weakness in Telerik.Web.UI.dll that can be exploited to disclose encryption keys (Telerik.Web.UI.DialogParametersEncryptionKey and/or the MachineKey), perform cross-site-scripting (XSS) attacks, compromise the ASP.NET ViewState, and/or upload and download files.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.