CVE-2024-47819
📋 TL;DR
This CVE describes a cross-site scripting (XSS) vulnerability in Umbraco CMS that allows attackers to execute malicious JavaScript in the context of authenticated users. If exploited against an administrative user, it could lead to privilege escalation and unauthorized access to protected content. The vulnerability affects Umbraco versions 14.0.0 through 14.3.0.
💻 Affected Systems
- Umbraco CMS
📦 What is this software?
Umbraco Cms by Umbraco
⚠️ Risk & Real-World Impact
Worst Case
Attackers could gain administrative privileges, elevate all users to admin, access sensitive content, and potentially take full control of the CMS instance.
Likely Case
Attackers could steal session cookies, perform actions as authenticated users, and potentially gain administrative access if targeting admin users.
If Mitigated
With proper access controls and user awareness, impact is limited to the specific user session being exploited.
🎯 Exploit Status
Exploitation requires social engineering to trick authenticated users into executing malicious JavaScript.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 14.3.1 or 15.0.0
Vendor Advisory: https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-c5g6-6xf7-qxp3
Restart Required: Yes
Instructions:
1. Backup your Umbraco instance and database. 2. Update to Umbraco version 14.3.1 or 15.0.0. 3. Restart the application. 4. Verify the update was successful.
🔧 Temporary Workarounds
Restrict Dictionary Section Access
allLimit access to the Dictionary section to only trusted administrative users who absolutely need it.
Configure user permissions in Umbraco backoffice to restrict Dictionary section access
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution
- Enable input validation and output encoding for all user-controllable inputs
🔍 How to Verify
Check if Vulnerable:
Check Umbraco version in the backoffice dashboard or web.config file; versions 14.0.0-14.3.0 are vulnerable.Check Version:
Check the Umbraco backoffice dashboard or examine the web.config file for version information.Verify Fix Applied:
Confirm Umbraco version is 14.3.1 or higher, or 15.0.0 or higher.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to Dictionary endpoints
- Suspicious JavaScript payloads in request logs
Network Indicators:
- Unexpected POST requests to administrative endpoints from non-admin users
SIEM Query:
source="umbraco_logs" AND (uri_path="*dictionary*" OR message="*script*" OR message="*alert*" OR message="*XSS*")