CVE-2025-3600
📋 TL;DR
An unsafe reflection vulnerability in Progress Telerik UI for AJAX allows attackers to cause unhandled exceptions that crash the hosting process, resulting in denial of service. This affects web applications using Telerik UI for AJAX versions 2011.2.712 through 2025.1.218.
💻 Affected Systems
- Progress Telerik UI for AJAX
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service for the affected web application, making it unavailable to legitimate users until the process is restarted.
Likely Case
Intermittent application crashes leading to service disruption and potential data loss for in-progress transactions.
If Mitigated
Application remains stable with proper input validation and exception handling in place.
🎯 Exploit Status
The vulnerability involves unsafe reflection that can be triggered via crafted input, making exploitation relatively straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2025.1.219 and later
Vendor Advisory: https://www.telerik.com/products/aspnet-ajax/documentation/knowledge-base/kb-security-unsafe-reflection-cve-2025-3600
Restart Required: Yes
Instructions:
1. Update Telerik UI for AJAX to version 2025.1.219 or later. 2. Rebuild and redeploy affected web applications. 3. Restart application hosting processes.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject malformed requests that could trigger the unsafe reflection.
Exception Handling Enhancement
allAdd global exception handlers to catch and log reflection-related exceptions without crashing the process.
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block suspicious reflection-related patterns.
- Isolate affected systems behind load balancers with health checks to automatically restart failed instances.
🔍 How to Verify
Check if Vulnerable:
Check the Telerik UI for AJAX assembly version in your web application's bin directory or referenced packages.Check Version:
Get-ChildItem -Path 'bin\Telerik.Web.UI.dll' | Select-Object -ExpandProperty VersionInfo (Windows PowerShell)Verify Fix Applied:
Verify the Telerik.UI.WebControls assembly version is 2025.1.219 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Unhandled exception logs mentioning ReflectionTypeLoadException or similar reflection errors
- Application crash events in Windows Event Log or system logs
Network Indicators:
- Sudden spikes in HTTP 500 errors
- Unusual patterns of requests to Telerik-specific endpoints
SIEM Query:
source='application_logs' AND (message LIKE '%ReflectionTypeLoadException%' OR message LIKE '%Telerik%' AND severity='ERROR')