CVE-2022-27468
📋 TL;DR
CVE-2022-27468 is a critical arbitrary file upload vulnerability in Monstaftp v2.10.3 that allows attackers to upload malicious files to the web server, potentially leading to remote code execution. This affects all systems running the vulnerable version of Monstaftp. Attackers can compromise the entire server if successful.
💻 Affected Systems
- Monstaftp
📦 What is this software?
Monsta Ftp by Monstaftp
⚠️ Risk & Real-World Impact
Worst Case
Complete server takeover with full administrative access, data theft, ransomware deployment, and lateral movement to other systems.
Likely Case
Webshell installation leading to persistent backdoor access, data exfiltration, and further server compromise.
If Mitigated
Limited impact with proper file upload restrictions, web application firewalls, and network segmentation in place.
🎯 Exploit Status
Exploitation is straightforward - attackers simply need to upload a malicious file to the vulnerable endpoint. Multiple proof-of-concept exploits are publicly available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v2.10.4 or later
Vendor Advisory: https://www.monstaftp.com/
Restart Required: Yes
Instructions:
1. Download the latest version from the official Monstaftp website. 2. Backup your current installation and configuration. 3. Replace the vulnerable files with the patched version. 4. Restart the web server service. 5. Verify the update was successful.
🔧 Temporary Workarounds
File Upload Restriction
allImplement strict file upload validation to block executable file types
# Configure web server to block uploads of .php, .asp, .jsp, .exe, .sh files
# Example Apache .htaccess: <FilesMatch "\.(php|asp|jsp|exe|sh)$">
Order Allow,Deny
Deny from all
</FilesMatch>
Web Application Firewall
allDeploy WAF rules to block malicious file upload attempts
# Example ModSecurity rule: SecRule FILES_TMPNAMES "@rx \.(php|asp|jsp|exe|sh)$" "id:1001,phase:2,deny,msg:'Malicious file upload attempt'"
# Configure WAF to inspect file upload content and headers
🧯 If You Can't Patch
- Immediately isolate the vulnerable system from the internet and restrict network access
- Implement strict file upload validation and monitoring for suspicious upload activities
🔍 How to Verify
Check if Vulnerable:
Check the Monstaftp version in the admin panel or by examining the software files. Version 2.10.3 is vulnerable.Check Version:
# Check version in Monstaftp admin interface or examine version.txt file if presentVerify Fix Applied:
Verify the version has been updated to 2.10.4 or later and test file upload functionality with restricted file types.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to Monstaftp endpoints
- Uploads of executable file types (.php, .asp, .jsp, .exe)
- Multiple failed upload attempts followed by successful upload
Network Indicators:
- HTTP POST requests to file upload endpoints with unusual file extensions
- Traffic patterns showing file uploads followed by immediate execution requests
SIEM Query:
source="web_server_logs" AND (uri="*upload*" OR uri="*file*" OR method="POST") AND (user_agent="*curl*" OR user_agent="*wget*" OR user_agent="*python*" OR status=200) AND (file_extension="php" OR file_extension="asp" OR file_extension="jsp" OR file_extension="exe")