CVE-2023-53914
📋 TL;DR
CVE-2023-53914 is an authentication bypass vulnerability in UliCMS 2023.1 that allows unauthenticated attackers to create administrative accounts with full system access through mass assignment. This affects all UliCMS 2023.1 installations with the admin interface accessible.
💻 Affected Systems
- UliCMS
📦 What is this software?
Ulicms by Ulicms
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attackers gain administrative control, install backdoors, exfiltrate data, and use the system for further attacks.
Likely Case
Attackers create persistent admin accounts to maintain access, modify content, steal sensitive data, and potentially deploy ransomware.
If Mitigated
Limited impact if proper network segmentation, WAF rules, and monitoring are in place to detect and block exploitation attempts.
🎯 Exploit Status
Exploit requires sending a crafted POST request to admin/index.php with specific parameters. Public exploit code is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2023.2 or later
Vendor Advisory: https://en.ulicms.de/
Restart Required: No
Instructions:
1. Backup your UliCMS installation. 2. Download and install UliCMS 2023.2 or later. 3. Replace all files with the new version. 4. Verify the admin interface functions correctly.
🔧 Temporary Workarounds
Restrict Admin Interface Access
allBlock external access to the admin interface using firewall rules or web server configuration.
# Apache: Deny from all except trusted IPs in .htaccess
# Nginx: allow 192.168.1.0/24; deny all; in server block
Input Validation Filter
allAdd input validation to filter mass assignment parameters before processing.
# Add to UserController: filter parameters to exclude 'admin', 'group_id' from mass assignment
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the admin interface.
- Deploy a WAF with rules to block POST requests containing admin user creation parameters.
🔍 How to Verify
Check if Vulnerable:
Check if running UliCMS 2023.1 by examining version files or admin interface footer.Check Version:
Check /version.txt or view admin interface footer for version information.Verify Fix Applied:
Confirm installation of UliCMS 2023.2 or later and test that unauthenticated POST requests to create admin users fail.📡 Detection & Monitoring
Log Indicators:
- POST requests to admin/index.php with parameters like 'username', 'password', 'group_id=1' from unauthenticated sources
- Unusual admin user creation events
Network Indicators:
- HTTP POST requests to /admin/index.php with user creation parameters from external IPs
SIEM Query:
source="web_logs" AND uri="/admin/index.php" AND method="POST" AND (params CONTAINS "group_id=1" OR params CONTAINS "admin=1")