CVE-2025-41052
📋 TL;DR
This vulnerability allows authenticated attackers to inject malicious scripts into appRain CMF through layout parameters, which then execute in other users' browsers when viewing affected pages. It affects appRain CMF version 4.0.5 users with developer 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
Attackers could steal administrator credentials, compromise the entire CMF installation, pivot to internal systems, or deploy ransomware payloads through authenticated user sessions.
Likely Case
Attackers with developer access inject malicious scripts to steal session cookies, redirect users to phishing sites, or perform unauthorized actions within the application.
If Mitigated
With proper input validation and output encoding, the malicious scripts would be neutralized, preventing execution while maintaining functionality.
🎯 Exploit Status
Requires authenticated developer access. Exploitation involves crafting malicious payloads for the 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 4.0.5
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-apprain-cmf
Restart Required: No
Instructions:
1. Upgrade appRain CMF to the latest version. 2. Apply vendor-provided security patches. 3. Verify the fix by testing the vulnerable parameters with XSS payloads.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation for the 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters to reject malicious scripts.
Output Encoding
allApply proper HTML encoding to user-controlled data before rendering in browser contexts.
🧯 If You Can't Patch
- Restrict developer access to trusted personnel only and implement strict access controls.
- Deploy a web application firewall (WAF) with XSS protection rules to block malicious payloads.
🔍 How to Verify
Check if Vulnerable:
Test by submitting XSS payloads to the '/apprain/developer/addons/update/canvasjs' endpoint with authenticated developer session.Check Version:
Check appRain CMF version in administration panel or configuration files.Verify Fix Applied:
After patching, attempt the same XSS payloads and verify they are properly sanitized or rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to '/apprain/developer/addons/update/canvasjs' with script tags or JavaScript in parameters
- Multiple failed authentication attempts followed by successful developer login
Network Indicators:
- HTTP requests containing '<script>' or 'javascript:' in 'data[Addon][layouts]' or 'data[Addon][layouts_except]' parameters
SIEM Query:
source="web_server" AND (uri="/apprain/developer/addons/update/canvasjs" AND (param="data[Addon][layouts]" OR param="data[Addon][layouts_except]") AND (value="*<script>*" OR value="*javascript:*"))