# CVE-2019-18935: Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability

- Exploited (CISA KEV): yes, added 2021-11-03, known ransomware use
- Published: 2019-12-11
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 99.7% (100th percentile)
- CWE: CWE-502

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.)

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | Rule published | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Before feed history | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | Before feed history | — | — |

### Microsoft Azure

- undated · listed · rule 99001012
  > Rule 99001012: Critical - 5 · 2 · Attempted Telerik WebUI insecure deserialization exploitation CVE-2019-18935
  Source: https://learn.microsoft.com/en-us/azure/web-application-firewall/afds/waf-front-door-drs
- undated · listed · rule 99001012
  > Rule 99001012: Critical - 5 · 2 · Attempted Telerik WebUI insecure deserialization exploitation CVE-2019-18935
  Source: https://learn.microsoft.com/en-us/azure/web-application-firewall/ag/application-gateway-crs-rulegroups-rules

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2019-18935 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2019-18935