CVE-2025-41057
📋 TL;DR
This vulnerability allows authenticated attackers to inject malicious scripts into appRain CMF through the rich text editor addon. When other users view the compromised content, the scripts execute in their browsers, potentially stealing session cookies or performing actions on their behalf. Only appRain CMF 4.0.5 installations with the developer addon enabled are affected.
💻 Affected Systems
- appRain CMF
📦 What is this software?
Apprain by Apprain
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, gain administrative access, deface websites, or redirect users to malicious sites.
Likely Case
Attackers with authenticated access could inject malicious scripts that execute when other users view compromised content, potentially stealing their session data.
If Mitigated
With proper input validation and output encoding, the malicious scripts would be rendered harmless as text rather than executable code.
🎯 Exploit Status
Requires authenticated access to the developer addon interface. Exploitation involves crafting malicious input to the specified parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch 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. Backup your current installation. 2. Download the latest version from the official appRain repository. 3. Replace the vulnerable files with the patched versions. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Developer Addon
allTemporarily disable the developer addon to prevent access to the vulnerable endpoint.
Edit appRain configuration to disable developer addon functionality
Input Validation Filter
allImplement server-side input validation for the affected parameters to sanitize HTML/JavaScript content.
Add input sanitization filters for 'data[Addon][layouts]' and 'data[Addon][layouts_except]' parameters
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads targeting the vulnerable parameters.
- Restrict access to the developer addon interface to only trusted administrators using IP whitelisting or additional authentication.
🔍 How to Verify
Check if Vulnerable:
Check if your appRain installation is version 4.0.5 and has the developer addon enabled with access to /apprain/developer/addons/update/rich_text_editor.Check Version:
Check appRain configuration files or admin panel for version information.Verify Fix Applied:
After updating, verify the version is 4.0.6 or later and test that malicious script input to the affected parameters is properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /apprain/developer/addons/update/rich_text_editor with script tags or JavaScript in parameters
- Multiple failed authentication attempts followed by successful access to developer addon
Network Indicators:
- HTTP requests containing script injection patterns in 'data[Addon][layouts]' or 'data[Addon][layouts_except]' parameters
SIEM Query:
source="web_server" AND (url_path="/apprain/developer/addons/update/rich_text_editor" AND (param_name="data[Addon][layouts]" OR param_name="data[Addon][layouts_except]") AND param_value MATCHES "<script|javascript:")