CVE-2023-6675
📋 TL;DR
This vulnerability allows attackers to upload malicious files (like web shells) to CyberMath web servers due to insufficient file type validation. It affects all CyberMath installations from version 1.4 up to (but not including) version 1.5. Attackers can gain unauthorized access and control over affected systems.
💻 Affected Systems
- National Keep Cyber Security Services CyberMath
📦 What is this software?
Cybermath by Nationalkeep
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing remote code execution, data theft, lateral movement, and persistent backdoor installation.
Likely Case
Web shell deployment leading to unauthorized access, data exfiltration, and potential ransomware deployment.
If Mitigated
Limited impact with proper file upload restrictions, but still potential for unauthorized file storage.
🎯 Exploit Status
Simple file upload exploitation with no authentication required makes this easily weaponizable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.5
Vendor Advisory: https://www.usom.gov.tr/bildirim/tr-24-0080
Restart Required: Yes
Instructions:
1. Download CyberMath v1.5 from official vendor sources. 2. Backup current installation and data. 3. Stop CyberMath service. 4. Install v1.5 following vendor documentation. 5. Restart CyberMath service. 6. Verify successful upgrade.
🔧 Temporary Workarounds
File Upload Restriction via Web Server
allConfigure web server to block upload of executable file types
# For Apache: Add to .htaccess or virtual host config
<FilesMatch "\.(php|asp|aspx|jsp|pl|py|sh)$">
Order Allow,Deny
Deny from all
</FilesMatch>
# For Nginx: Add to server block
location ~ \.(php|asp|aspx|jsp|pl|py|sh)$ {
deny all;
}
Disable File Upload Functionality
allTemporarily disable file upload features in CyberMath configuration
# Edit CyberMath configuration file
# Set upload_enabled = false or equivalent setting
🧯 If You Can't Patch
- Implement strict WAF rules to block file uploads containing executable content
- Deploy network segmentation to isolate CyberMath servers from critical assets
🔍 How to Verify
Check if Vulnerable:
Check CyberMath version via admin interface or configuration files. If version is 1.4.x, the system is vulnerable.Check Version:
# Check version in CyberMath admin panel or config files
# Typically in /var/www/cybermath/config/version.txt or similarVerify Fix Applied:
Verify version shows 1.5 or higher and test file upload functionality with restricted file types.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to upload directories
- POST requests with file uploads to unexpected endpoints
- Execution of uploaded files with suspicious extensions
Network Indicators:
- HTTP POST requests with file uploads to CyberMath endpoints
- Outbound connections from CyberMath server to unknown IPs
SIEM Query:
source="cybermath" AND (http_method="POST" AND uri_path CONTAINS "upload") AND (file_extension="php" OR file_extension="jsp" OR file_extension="asp" OR file_extension="aspx")