CVE-2025-41049
📋 TL;DR
This vulnerability allows authenticated attackers to inject malicious scripts into appRain CMF through layout parameters, which then execute in other users' browsers. It affects appRain CMF version 4.0.5 users who have developer/addon management access. The stored XSS can lead to session hijacking, data theft, or unauthorized actions.
💻 Affected Systems
- appRain CMF
📦 What is this software?
Apprain by Apprain
⚠️ Risk & Real-World Impact
Worst Case
Administrator account compromise leading to full system takeover, data exfiltration, or malware distribution to all users.
Likely Case
Session hijacking of other authenticated users, credential theft, or unauthorized actions performed in victims' contexts.
If Mitigated
Limited to authenticated users only, with proper input validation preventing successful exploitation.
🎯 Exploit Status
Requires authenticated access to the vulnerable endpoint and knowledge of XSS payloads.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 4.0.5 (check vendor for specific version)
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-apprain-cmf
Restart Required: No
Instructions:
1. Check appRain CMF version. 2. Update to latest patched version from official vendor. 3. Verify update applied successfully. 4. Test addon management functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation for 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters to sanitize HTML/JavaScript content.
Content Security Policy
allImplement strict Content Security Policy headers to mitigate XSS impact by restricting script execution sources.
🧯 If You Can't Patch
- Restrict access to /apprain/developer/addons/update/appform endpoint to only essential administrators.
- Implement web application firewall rules to block XSS payloads in the affected parameters.
🔍 How to Verify
Check if Vulnerable:
Check if running appRain CMF version 4.0.5 and test if unsanitized input in 'data[Addon][layouts]' parameter executes as JavaScript.Check Version:
Check appRain CMF configuration files or admin panel for version information.Verify Fix Applied:
After update, test that HTML/JavaScript input in the vulnerable parameters is properly sanitized and doesn't execute.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /apprain/developer/addons/update/appform with script tags or JavaScript in parameters
- Multiple failed login attempts followed by successful access to developer features
Network Indicators:
- HTTP requests containing <script> tags or JavaScript functions in 'data[Addon][layouts]' parameter
SIEM Query:
source="web_logs" AND uri_path="/apprain/developer/addons/update/appform" AND (request_body CONTAINS "<script>" OR request_body CONTAINS "javascript:")