CVE-2021-38727
📋 TL;DR
CVE-2021-38727 is a SQL injection vulnerability in FUEL CMS that allows attackers to execute arbitrary SQL commands via the 'col' parameter in the logs module. This affects all systems running FUEL CMS 1.5.0, potentially compromising database confidentiality, integrity, and availability.
💻 Affected Systems
- FUEL CMS
📦 What is this software?
Fuel Cms by Thedaylightstudio
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise leading to data theft, data manipulation, authentication bypass, and potential remote code execution via database functions.
Likely Case
Unauthorized data access and extraction, including sensitive user information, configuration data, and potentially administrative credentials.
If Mitigated
Limited impact if proper input validation and parameterized queries are implemented, restricting SQL injection attempts.
🎯 Exploit Status
Exploitation requires authentication to the FUEL CMS admin interface. Public proof-of-concept demonstrates SQL injection via the 'col' parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.1 and later
Vendor Advisory: https://github.com/daylightstudio/FUEL-CMS/issues/582
Restart Required: No
Instructions:
1. Upgrade FUEL CMS to version 1.5.1 or later. 2. Download the latest version from the official repository. 3. Replace vulnerable files with patched versions. 4. Verify the fix by testing the /fuel/index.php/fuel/logs/items endpoint.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for the 'col' parameter to only allow expected values.
Modify application code to validate 'col' parameter against a whitelist of allowed column names
WAF Rule
allDeploy web application firewall rules to block SQL injection attempts targeting the logs endpoint.
Configure WAF to detect and block patterns like UNION SELECT, information_schema queries, and SQL keywords in the 'col' parameter
🧯 If You Can't Patch
- Restrict access to /fuel/index.php/fuel/logs/items endpoint using network ACLs or authentication requirements
- Implement database-level controls: use least privilege database accounts, enable SQL injection protection features
🔍 How to Verify
Check if Vulnerable:
Test the /fuel/index.php/fuel/logs/items endpoint with SQL injection payloads in the 'col' parameter while authenticated.Check Version:
Check FUEL CMS version in application configuration or via admin interfaceVerify Fix Applied:
After patching, attempt SQL injection on the same endpoint and verify it's blocked or sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL queries in database logs
- Multiple failed login attempts followed by access to logs endpoint
- HTTP requests with SQL keywords in 'col' parameter
Network Indicators:
- HTTP POST/GET requests to /fuel/index.php/fuel/logs/items with suspicious 'col' parameter values
SIEM Query:
source="web_logs" AND uri="/fuel/index.php/fuel/logs/items" AND (param="col" AND value MATCH "(?i)(union|select|from|where|information_schema)")