CVE-2021-36570
📋 TL;DR
This CSRF vulnerability in FUEL-CMS allows attackers to trick authenticated administrators into executing unauthorized actions, specifically deleting permissions via crafted requests. Any FUEL-CMS installation with admin access is affected, potentially leading to privilege escalation or system compromise.
💻 Affected Systems
- FUEL-CMS
📦 What is this software?
Fuel Cms by Thedaylightstudio
⚠️ Risk & Real-World Impact
Worst Case
Attackers could delete critical permissions, gain administrative access, and execute arbitrary code leading to complete system takeover.
Likely Case
Unauthorized deletion of permissions causing privilege escalation or disruption of normal administrative functions.
If Mitigated
Limited impact with proper CSRF protections and admin session management in place.
🎯 Exploit Status
Exploit requires tricking authenticated admin to visit malicious page or click crafted link.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.4.14 or later
Vendor Advisory: https://github.com/daylightstudio/FUEL-CMS/issues/579
Restart Required: No
Instructions:
1. Backup current installation. 2. Update to FUEL-CMS 1.4.14 or later. 3. Verify CSRF tokens are properly implemented in all forms.
🔧 Temporary Workarounds
Implement CSRF Protection
allAdd CSRF tokens to all forms and validate them server-side
Modify application code to include and validate CSRF tokens
Restrict Admin Access
allLimit admin panel access to specific IP addresses or networks
Add IP restrictions in .htaccess or web server configuration
🧯 If You Can't Patch
- Implement strict SameSite cookie policies and require re-authentication for sensitive actions
- Monitor admin activity logs for unauthorized permission deletion attempts
🔍 How to Verify
Check if Vulnerable:
Check if FUEL-CMS version is 1.4.13 or earlier and lacks CSRF protection on /permissions/delete endpointCheck Version:
Check FUEL-CMS version in application configuration or admin panelVerify Fix Applied:
Verify version is 1.4.14+ and test that CSRF tokens are required for permission deletion📡 Detection & Monitoring
Log Indicators:
- Multiple permission deletion requests from same session
- Admin actions without proper referrer headers
Network Indicators:
- POST requests to /permissions/delete/ without CSRF tokens
- Cross-origin requests to admin endpoints
SIEM Query:
source="web_logs" AND (uri="/permissions/delete/*" AND NOT csrf_token=*)