CVE-2025-55887
📋 TL;DR
A Cross-Site Scripting (XSS) vulnerability in the ARD meal reservation service allows attackers to inject malicious JavaScript via the transactionID parameter. This enables session hijacking, cookie theft, and unauthorized actions on behalf of victims. All users accessing the vulnerable transaction confirmation page are affected.
💻 Affected Systems
- ARD meal reservation service
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, theft of sensitive personal/financial data, and unauthorized transactions performed on behalf of victims.
Likely Case
Session hijacking leading to unauthorized access to meal reservation accounts and potential theft of personal information.
If Mitigated
Limited impact with proper input validation and output encoding preventing script execution.
🎯 Exploit Status
Proof of concept available on GitHub. Exploitation requires crafting a malicious URL with JavaScript payload in transactionID parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown specific version - check vendor advisory
Vendor Advisory: https://services.ard.fr/index.php
Restart Required: No
Instructions:
1. Apply vendor patch from ARD advisory. 2. Update ARD meal reservation service to latest secure version. 3. Test transaction confirmation page functionality.
🔧 Temporary Workarounds
Input Validation and Output Encoding
allImplement server-side validation of transactionID parameter and proper output encoding on the confirmation page.
Implement input validation: allow only alphanumeric characters in transactionID
Apply HTML entity encoding to transactionID output: htmlspecialchars($transactionID, ENT_QUOTES, 'UTF-8')
Web Application Firewall (WAF) Rules
allConfigure WAF to block requests containing JavaScript patterns in transactionID parameter.
Add WAF rule: Block if transactionID contains <script>, javascript:, or common XSS payload patterns
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution sources
- Disable or restrict access to the vulnerable transaction confirmation page until patched
🔍 How to Verify
Check if Vulnerable:
Test by accessing the transaction confirmation page with a payload like: https://target.com/confirm?transactionID=<script>alert('XSS')</script>Check Version:
Check ARD service version via web interface or contact vendor supportVerify Fix Applied:
Attempt the same XSS payload and verify no script execution occurs. Check that transactionID is properly sanitized in page source.📡 Detection & Monitoring
Log Indicators:
- HTTP requests with suspicious characters (<, >, script, javascript:) in transactionID parameter
- Multiple failed transaction confirmations from same IP
Network Indicators:
- Unusual spikes in traffic to transaction confirmation page
- Requests containing XSS payload patterns in URLs
SIEM Query:
source=web_logs transactionID=*<script>* OR transactionID=*javascript:* | stats count by src_ip