CVE-2024-43376
📋 TL;DR
This vulnerability in Umbraco CMS allows attackers to obtain stack trace information from Management API endpoints even when debug mode is disabled. This affects all Umbraco installations using vulnerable versions, potentially exposing internal system details that could aid further attacks.
💻 Affected Systems
- Umbraco CMS
📦 What is this software?
Umbraco Cms by Umbraco
⚠️ Risk & Real-World Impact
Worst Case
Attackers obtain detailed stack traces revealing internal system architecture, file paths, method names, and potentially sensitive configuration details that could facilitate targeted attacks.
Likely Case
Information disclosure of internal system structure that could help attackers understand the application's implementation and identify other potential vulnerabilities.
If Mitigated
Limited information exposure with no direct system compromise, but still provides reconnaissance value to attackers.
🎯 Exploit Status
Exploitation requires authenticated access to Management API endpoints. The vulnerability is straightforward to trigger once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 14.1.2
Vendor Advisory: https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-77gj-crhp-3gvx
Restart Required: Yes
Instructions:
1. Backup your Umbraco installation and database. 2. Update Umbraco CMS to version 14.1.2 or later via NuGet package manager. 3. Restart the application pool or IIS service. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Restrict Management API Access
allLimit access to Management API endpoints using firewall rules or application-level authorization.
Implement Custom Error Handling
allOverride default error handling to suppress stack trace information in API responses.
🧯 If You Can't Patch
- Implement strict access controls to limit Management API access to authorized administrators only
- Monitor API logs for unusual access patterns or attempts to trigger error conditions
🔍 How to Verify
Check if Vulnerable:
Access Management API endpoints that might return errors and check if stack trace information is included in responses when debug mode is disabled.Check Version:
Check the Umbraco version in the admin dashboard or inspect the web.config file for version information.Verify Fix Applied:
After patching, test the same endpoints to confirm stack traces are no longer returned in production mode.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to Management API endpoints
- Multiple error responses from API endpoints
Network Indicators:
- HTTP requests to Management API endpoints returning unusually large response sizes
SIEM Query:
source="umbraco_logs" AND (uri_path="/umbraco/api/*" AND response_size>threshold) OR (error_message CONTAINS "stack trace")