Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2017-11357

Telerik UI for ASP.NET AJAX Arbitrary File Access

Progress Software / Telerik UI for ASP.NET AJAX

Watch CVE-2017-11357 Browse KEV feed
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
77.7%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2017-11357 is an unauthenticated vulnerability affecting Progress Software Telerik UI for ASP.NET AJAX. Progress Telerik UI for ASP.NET AJAX before R2 2017 SP2 does not properly restrict user input to...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Progress Software / Telerik UI for ASP.NET AJAX.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Telerik UI for ASP.NET AJAX Arbitrary File Access

Progress Telerik UI for ASP.NET AJAX before R2 2017 SP2 does not properly restrict user input to RadAsyncUpload, which allows remote attackers to perform arbitrary file uploads or execute arbitrary code.

Published
23 Aug 2017
Exploitation Reported
26 Jan 2023
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nessus_scanner cisa dotnet malware ransomware

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 26 Jan 2023

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 26 Jan 2023

Malware families have been linked to exploitation of this CVE.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2023-01-26 00:00 UTC
CVE 2026-08-14 04:30 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nessus https://www.tenable.com/plugins/nessus/112522 02 Jun 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

77.7%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Unrestricted Upload of File with Dangerous Type CWE-434

All CVSS Scores

CVSS v3.1 9.8 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v2.0 7.5 High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Timeline

From disclosure to observed exploitation

  1. 04:30 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  2. 09:27 UTC

    Nessus plugin available

    Scanner coverage available

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 00:00 UTC

    First public exploitation report

    Exploit observed in malware

  5. 17:00 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2017-11357

Sample API response 
{
  "cve_id": "CVE-2017-11357",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.77679,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}