CVE-2022-50939
📋 TL;DR
CVE-2022-50939 is a critical file upload vulnerability in e107 CMS version 3.2.1 that allows authenticated administrators to overwrite arbitrary server files through path traversal. Attackers with admin privileges can use directory traversal sequences in the upload_caption parameter to compromise critical system files. This affects all e107 CMS 3.2.1 installations with administrative users.
💻 Affected Systems
- e107 CMS
📦 What is this software?
E107 by E107
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through overwriting system files, configuration files, or web shells leading to remote code execution and data exfiltration.
Likely Case
Administrative account takeover leading to website defacement, data manipulation, or installation of backdoors.
If Mitigated
Limited impact if proper file permissions and admin account security are enforced, though file overwrite capability remains.
🎯 Exploit Status
Exploit requires administrative credentials. Public exploit code available on Exploit-DB (ID 50910).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.2 or later
Vendor Advisory: https://e107.org/
Restart Required: No
Instructions:
1. Backup your e107 installation and database. 2. Download e107 CMS version 3.2.2 or later from e107.org. 3. Replace the vulnerable image.php file in the admin directory. 4. Verify the patch by testing the upload functionality.
🔧 Temporary Workarounds
Disable Remote URL Upload
allTemporarily disable the vulnerable Media Manager remote URL upload functionality.
# Rename or remove the vulnerable file
mv /path/to/e107/admin/image.php /path/to/e107/admin/image.php.disabled
Restrict Admin Access
linuxImplement IP whitelisting for admin interface and enforce strong authentication.
# Add to .htaccess for Apache
Order deny,allow
Deny from all
Allow from 192.168.1.0/24
# For Nginx
allow 192.168.1.0/24;
deny all;
🧯 If You Can't Patch
- Implement strict file permission controls on web root and system directories
- Monitor admin account activity and implement multi-factor authentication
🔍 How to Verify
Check if Vulnerable:
Check if running e107 version 3.2.1 and examine image.php in admin directory for lack of path traversal sanitization.Check Version:
Check e107 version in admin panel or examine e107_config.php for version information.Verify Fix Applied:
Verify e107 version is 3.2.2 or later and test upload functionality with traversal sequences to confirm rejection.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /admin/image.php with ../ sequences in parameters
- File modification events in system directories from web user
Network Indicators:
- Unusual file upload patterns to admin interface
- Multiple failed upload attempts with traversal sequences
SIEM Query:
source="web_logs" AND uri_path="/admin/image.php" AND (http_method="POST" AND (param="upload_caption" AND value="*../*"))