CVE-2025-41350
📋 TL;DR
A stored Cross-site Scripting (XSS) vulnerability in WinPlus v24.11.27 allows attackers to inject malicious scripts via the 'descripcion' parameter in POST requests. This could enable session cookie theft when authenticated users view the compromised content. Organizations using WinPlus v24.11.27 from Informática del Este are affected.
💻 Affected Systems
- WinPlus by Informática del Este
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator session cookies, gain full system access, and potentially compromise the entire WinPlus environment and connected systems.
Likely Case
Attackers steal user session cookies to impersonate legitimate users, access sensitive data, and perform unauthorized actions within the application.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before execution, preventing session theft.
🎯 Exploit Status
Exploitation requires the attacker to have access to submit POST requests to the vulnerable endpoint, but no authentication is needed for the initial payload injection.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/stored-cross-site-scripting-xss-winplus-informatica-del-este
Restart Required: No
Instructions:
1. Monitor vendor advisory for patch release. 2. Apply patch when available. 3. Test in non-production environment first. 4. Deploy to production systems.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize the 'descripcion' parameter by removing or encoding HTML/JavaScript special characters.
Web Application Firewall (WAF) Rules
allDeploy WAF rules to block requests containing suspicious script patterns in the 'descripcion' parameter.
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution sources
- Disable or restrict access to the '/WinplusPortal/ws/sWinplus.svc/json/savesoldoc_post' endpoint if not essential
🔍 How to Verify
Check if Vulnerable:
Test by submitting a POST request to '/WinplusPortal/ws/sWinplus.svc/json/savesoldoc_post' with a script payload in the 'descripcion' parameter and check if it executes when viewed.Check Version:
Check WinPlus version in application interface or configuration files (specific command depends on deployment).Verify Fix Applied:
Repeat the vulnerability test after applying fixes; script payloads should be sanitized or blocked and not execute.📡 Detection & Monitoring
Log Indicators:
- POST requests to '/WinplusPortal/ws/sWinplus.svc/json/savesoldoc_post' with script-like content in parameters
- Unusual user sessions or cookie theft alerts
Network Indicators:
- HTTP traffic containing script tags or JavaScript in POST data to the vulnerable endpoint
SIEM Query:
source="web_server" AND (url_path="/WinplusPortal/ws/sWinplus.svc/json/savesoldoc_post" AND http_method="POST" AND (param="descripcion" AND value CONTAINS "<script>" OR "javascript:"))