CVE-2023-39939
📋 TL;DR
This SQL injection vulnerability in LuxCal Web Calendar allows remote unauthenticated attackers to execute arbitrary SQL queries against the database. Affected users are those running LuxCal Web Calendar versions prior to 5.2.3M (MySQL) or 5.2.3L (SQLite).
💻 Affected Systems
- LuxCal Web Calendar
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including data theft, data manipulation, privilege escalation, and potential server takeover via SQL injection to RCE chaining.
Likely Case
Unauthorized access to sensitive calendar data, user credentials, and potential data corruption.
If Mitigated
Limited impact with proper input validation and database permissions, but still significant risk due to unauthenticated nature.
🎯 Exploit Status
SQL injection vulnerabilities are commonly exploited and tooling exists for automated exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.2.3M (MySQL) or 5.2.3L (SQLite)
Vendor Advisory: https://www.luxsoft.eu/
Restart Required: No
Instructions:
1. Download latest version from luxsoft.eu 2. Backup database and files 3. Replace application files with patched version 4. Verify functionality
🔧 Temporary Workarounds
Web Application Firewall
allDeploy WAF with SQL injection protection rules
Network Segmentation
allRestrict access to LuxCal application to trusted networks only
🧯 If You Can't Patch
- Implement strict input validation and parameterized queries in custom code
- Apply database-level permissions to limit application user privileges
🔍 How to Verify
Check if Vulnerable:
Check LuxCal version in admin panel or by examining source filesCheck Version:
Check admin panel or examine includes/version.php fileVerify Fix Applied:
Confirm version is 5.2.3M or 5.2.3L or higher📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages
- Multiple failed login attempts with SQL syntax
- Unexpected database queries
Network Indicators:
- SQL keywords in HTTP requests
- Unusual parameter values in calendar requests
SIEM Query:
web.url:*luxcal* AND (http.method:POST OR http.method:GET) AND (http.uri:*sql* OR http.uri:*union* OR http.uri:*select*)