CVE-2023-30266
📋 TL;DR
CLTPHP versions up to 6.0 contain an unrestricted file upload vulnerability that allows attackers to upload malicious files to the server. This affects all systems running vulnerable CLTPHP installations, potentially leading to remote code execution.
💻 Affected Systems
- CLTPHP
📦 What is this software?
Cltphp by Cltphp
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Webshell upload allowing persistent backdoor access, data exfiltration, and further exploitation of the server.
If Mitigated
File upload attempts blocked or sanitized, preventing malicious file execution.
🎯 Exploit Status
Simple file upload bypass with readily available exploit code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a maintained version or implementing workarounds.
🔧 Temporary Workarounds
File Upload Restriction
allImplement strict file type validation and extension filtering on upload endpoints.
Web Application Firewall Rules
allDeploy WAF rules to block malicious file upload patterns and extensions.
🧯 If You Can't Patch
- Disable file upload functionality entirely if not required.
- Implement file upload quarantine and manual review process.
🔍 How to Verify
Check if Vulnerable:
Check CLTPHP version in admin panel or configuration files. Test file upload with malicious extensions.Check Version:
Check /admin/index.php or configuration files for version information.Verify Fix Applied:
Attempt to upload files with dangerous extensions (.php, .jsp, .asp) and verify they are rejected.📡 Detection & Monitoring
Log Indicators:
- File upload attempts with suspicious extensions
- Large number of upload requests
- Uploads to unusual directories
Network Indicators:
- POST requests to upload endpoints with executable files
- Unusual outbound connections after upload
SIEM Query:
source="web_logs" AND (uri="*upload*" OR uri="*file*" OR method="POST") AND (extension=".php" OR extension=".jsp" OR extension=".asp")