Progress · Telerik UI for ASP.NET AJAX
CVE-2019-18935
Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability
What it is
Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. Exploitation can result in remote code execution. (As of 2020.1.114, a default setting prevents the exploit. In 2019.3.1023, but not earlier versions, a non-default setting can prevent exploitation.)
CISA: Progress Telerik UI for ASP.NET AJAX contains a deserialization of untrusted data vulnerability through RadAsyncUpload which leads to code execution on the server in the context of the w3wp.exe process.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: May 3, 2022
- Added to the CISA list
- November 3, 2021
- Published
- December 11, 2019
- Severity
- Critical 9.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 99.7% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-502
- More details
- NVD · CVE.org · CISA
All references (10)
- https://www.telerik.com/support/whats-new/release-history
- https://codewhitesec.blogspot.com/2019/02/telerik-revisited.html
- https://www.telerik.com/support/kb/aspnet-ajax/details/allows-javascriptserializer-deserialization
- https://github.com/bao7uo/RAU_crypto
- https://know.bishopfox.com/research/cve-2019-18935-remote-code-execution-in-telerik-ui
- https://github.com/noperator/CVE-2019-18935
- http://packetstormsecurity.com/files/155720/Telerik-UI-Remote-Code-Execution.html
- https://www.telerik.com/support/whats-new/aspnet-ajax/release-history/ui-for-asp-net-ajax-r1-2020-%28version-…
- http://packetstormsecurity.com/files/159653/Telerik-UI-ASP.NET-AJAX-RadAsyncUpload-Deserialization.html
- https://www.bleepingcomputer.com/news/security/us-federal-agency-hacked-using-old-telerik-bug-to-steal-data/
More exploited flaws from Progress
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Aug 7, 2026 | Command Injection | LoadMaster | Critical 9.6 | 99.8% |
| Mar 3, 2025 | Path Traversal | WhatsUp Gold | Critical 9.8 | 99.3% |
| Nov 18, 2024 | OS Command Injection | Kemp LoadMaster | Critical 10.0 | 95% |
| Sep 16, 2024 | SQL Injection | WhatsUp Gold | Critical 9.8 | 93% |
| Jun 13, 2024 | Authentication Bypass by Spoofing | Telerik Report Server | Critical 9.8 | 97% |
| Oct 5, 2023 | Deserialization of Untrusted Data | WS_FTP Server | Critical 10.0 | 90% |
| Jun 2, 2023 | SQL Injection | MOVEit Transfer | Critical 9.8 | 99.9% |
| Nov 3, 2021 | Telerik UI for ASP.NET AJAX and Sitefinity Cryptographic Weakness | ASP.NET AJAX and Sitefinity | Critical 9.8 | 75% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.