CVE-2024-42991
📋 TL;DR
MCMS v5.4.1 has an unauthenticated front-end file upload vulnerability that allows attackers to upload malicious files and execute arbitrary commands on the server. This affects all systems running the vulnerable version of MCMS content management system. Attackers can gain complete control over affected web servers.
💻 Affected Systems
- MCMS
📦 What is this software?
Mcms by Mingsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise leading to data theft, ransomware deployment, lateral movement within the network, and persistent backdoor installation.
Likely Case
Webshell deployment allowing remote command execution, data exfiltration, and potential privilege escalation to underlying operating system.
If Mitigated
Limited impact if file uploads are disabled or strict file type validation is implemented, though the vulnerability still exists.
🎯 Exploit Status
The vulnerability is straightforward to exploit with publicly available proof-of-concept code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://gitee.com/mingSoft/MCMS/issues/IAHN9F
Restart Required: No
Instructions:
1. Monitor the MCMS repository for security updates. 2. Apply any available patches immediately. 3. Consider upgrading to a newer version if available.
🔧 Temporary Workarounds
Disable File Uploads
allTemporarily disable front-end file upload functionality in MCMS configuration
Edit MCMS configuration to remove or disable upload endpoints
Implement Web Application Firewall Rules
allBlock malicious file upload attempts at the WAF level
Configure WAF to block requests to upload endpoints with executable file extensions
🧯 If You Can't Patch
- Implement strict file type validation and whitelist only safe extensions
- Isolate MCMS instance in a DMZ with strict network segmentation
🔍 How to Verify
Check if Vulnerable:
Check if MCMS version is 5.4.1 and test file upload functionality with malicious payloadsCheck Version:
Check MCMS configuration files or admin panel for version informationVerify Fix Applied:
Test file upload functionality with various file types to ensure only allowed extensions are accepted📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads with executable extensions
- Multiple failed upload attempts
- Uploads from suspicious IP addresses
Network Indicators:
- HTTP POST requests to upload endpoints with unusual file types
- Traffic patterns indicating webshell communication
SIEM Query:
source="web_logs" AND (uri_path="*upload*" OR uri_path="*file*" OR method="POST") AND (user_agent="*curl*" OR user_agent="*wget*" OR file_extension="*.php" OR file_extension="*.jsp" OR file_extension="*.asp")