Background exploitation KEV catalog Ransomware No authentication
CVE-2019-18935

Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability

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…

CheckOps priority index
9.9/10 Patch within 24 h
Severity9.8
Probability10.0
Exploitation5/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 99.7% higher than 99.95% of CVEs
CVSS 3.1 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 1,826 days 03 Nov 2021
CISA due date 03 May 2022 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 5 / 5

  • KEV catalog (CISA)03 Nov 2021
  • Exploited in EUVD (ENISA)03 Nov 2021
  • Used by ransomwareyes
  • EPSS above 10 %99.7%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.)

Affected products

Telerik UI for ASP.NET AJAX
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 99.7%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-8037Progress LoadMaster Command Injection Vulnerability
    8.6 · Actively exploited
  • CVE-2024-4885Progress WhatsUp Gold Path Traversal Vulnerability
    9.3 · Background exploitation
  • CVE-2024-1212Progress Kemp LoadMaster OS Command Injection Vulnerability
    9.3 · Background exploitation
  • CVE-2024-6670Progress WhatsUp Gold SQL Injection Vulnerability
    9.7 · Background exploitation
  • CVE-2024-4358Progress Telerik Report Server Authentication Bypass by Spoofing Vulnerability
    9.2 · Background exploitation
  • CVE-2023-40044Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability
    9.7 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities