CVE-2022-50940
📋 TL;DR
Knap Advanced PHP Login 3.1.3 contains a persistent cross-site scripting (XSS) vulnerability in the name parameter. Attackers can inject malicious scripts that execute in backend modules when administrators view user or activity logs, potentially leading to session hijacking or phishing attacks. This affects all installations using the vulnerable version.
💻 Affected Systems
- Knap Advanced PHP Login
⚠️ Risk & Real-World Impact
Worst Case
Administrator account compromise leading to full system takeover, data theft, or deployment of additional malware.
Likely Case
Session hijacking of administrators, credential theft via phishing, or defacement of backend interfaces.
If Mitigated
Limited impact with proper input validation and output encoding, though backend functionality remains at risk.
🎯 Exploit Status
Exploitation requires user registration or account creation to inject payload into name parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://laravel-vuejs.com/
Restart Required: No
Instructions:
1. Check vendor website for updated version. 2. If available, download and replace vulnerable files. 3. Test functionality after update.
🔧 Temporary Workarounds
Input Validation and Sanitization
allAdd server-side validation to sanitize name parameter input before storage.
Modify PHP code to use htmlspecialchars() or filter_var() on name parameter
Output Encoding
allEnsure all user-controlled data is properly encoded when displayed in backend modules.
Implement htmlentities() or similar encoding when echoing name data
🧯 If You Can't Patch
- Restrict access to backend modules to trusted IP addresses only
- Implement web application firewall (WAF) rules to block XSS payloads in name parameter
🔍 How to Verify
Check if Vulnerable:
Check if running Knap Advanced PHP Login version 3.1.3 by examining version files or configuration.Check Version:
grep -r 'version' /path/to/knap/installation/ or check config filesVerify Fix Applied:
Test by attempting to inject basic XSS payload in name field during registration and checking if it executes in backend.📡 Detection & Monitoring
Log Indicators:
- Unusual long name entries in user registration logs
- JavaScript or HTML tags in name field logs
Network Indicators:
- POST requests with script tags in name parameter to registration endpoints
SIEM Query:
source="web_logs" AND (name="*<script>*" OR name="*javascript:*")