CVE-2025-41055
📋 TL;DR
This vulnerability allows authenticated attackers to inject malicious scripts into appRain CMF through layout parameters, which execute when other users view affected pages. It affects all users of appRain CMF version 4.0.5 who have access to the developer addon update functionality. 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 user accounts, deface websites, or perform actions as authenticated users, potentially leading to full system compromise.
Likely Case
Attackers with developer access inject malicious scripts to steal session cookies or perform limited unauthorized actions within the application.
If Mitigated
With proper input validation and output encoding, the vulnerability would be prevented, limiting impact to attempted but unsuccessful injection attempts.
🎯 Exploit Status
Exploitation requires authenticated access to the developer interface. No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 4.0.6 or later
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-apprain-cmf
Restart Required: No
Instructions:
1. Upgrade appRain CMF to version 4.0.6 or later. 2. Apply the patch from the vendor advisory. 3. Verify the fix by testing the affected parameters.
🔧 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.
Output Encoding
allApply proper output encoding when displaying user-controlled data from the affected parameters to prevent script execution.
🧯 If You Can't Patch
- Restrict access to the /apprain/developer/addons/update/dialogs endpoint to trusted administrators only.
- Implement a web application firewall (WAF) with XSS protection rules to block malicious payloads.
🔍 How to Verify
Check if Vulnerable:
Test by submitting JavaScript payloads to 'data[Addon][layouts]' or 'data[Addon][layouts_except]' parameters in the developer addon update dialog and checking if they execute.Check Version:
Check the appRain CMF version in the admin panel or configuration files.Verify Fix Applied:
After patching, attempt the same test payloads and verify they are properly sanitized or blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /apprain/developer/addons/update/dialogs with script tags or JavaScript in parameters
- Multiple failed login attempts followed by access to developer features
Network Indicators:
- HTTP requests containing script payloads in 'data[Addon][layouts]' or 'data[Addon][layouts_except]' parameters
SIEM Query:
source="web_logs" AND (url_path="/apprain/developer/addons/update/dialogs" AND (param="data[Addon][layouts]" OR param="data[Addon][layouts_except]") AND (content CONTAINS "<script>" OR content CONTAINS "javascript:"))