CVE-2023-34738
📋 TL;DR
CVE-2023-34738 is an arbitrary file upload vulnerability in Chemex asset management software that allows attackers to upload malicious files to the server. This affects all Chemex installations up to version 3.7.1. Attackers can potentially execute arbitrary code on the server.
💻 Affected Systems
- Chemex
📦 What is this software?
Chemex by Chemex
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via remote code execution, leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Webshell upload leading to server control, data exfiltration, or lateral movement within the network.
If Mitigated
Limited impact if file uploads are restricted to authenticated users and proper file validation is implemented.
🎯 Exploit Status
Exploitation requires authentication but is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 3.7.2 or later
Vendor Advisory: https://github.com/celaraze/chemex/issues/64
Restart Required: No
Instructions:
1. Backup your Chemex installation and database. 2. Update Chemex to version 3.7.2 or later. 3. Verify the update completed successfully.
🔧 Temporary Workarounds
Restrict file upload permissions
allConfigure web server to block upload of executable file types
# Configure nginx location block to deny .php, .sh, etc.
# Configure Apache .htaccess to restrict uploads
Implement file validation
allAdd server-side file type validation before accepting uploads
# Implement file extension and MIME type validation in application code
🧯 If You Can't Patch
- Restrict access to Chemex interface to trusted users only
- Implement web application firewall rules to block suspicious file uploads
🔍 How to Verify
Check if Vulnerable:
Check Chemex version in admin interface or via package manager. Versions 3.7.1 and earlier are vulnerable.Check Version:
Check Chemex admin dashboard or review installation files for version information.Verify Fix Applied:
Verify version is 3.7.2 or later and test file upload functionality with malicious files.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to Chemex upload directories
- Uploads of executable file types (.php, .sh, .exe)
- Multiple failed upload attempts
Network Indicators:
- POST requests to Chemex upload endpoints with suspicious file content
- Unusual outbound connections from Chemex server
SIEM Query:
source="chemex" AND (event="file_upload" AND file_extension IN ("php", "sh", "exe", "jsp"))