CVE-2018-16974
📋 TL;DR
This vulnerability in Elefant CMS allows remote attackers to execute arbitrary PHP code on affected servers. Attackers can bypass file upload restrictions by removing .htaccess protections and uploading malicious PHP files with crafted filenames. All Elefant CMS installations before version 2.0.7 are affected.
💻 Affected Systems
- Elefant CMS
📦 What is this software?
Elefant by Elefantcms
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise allowing arbitrary code execution, data theft, and potential lateral movement within the network.
Likely Case
Webshell deployment leading to data exfiltration, defacement, or use as part of a botnet.
If Mitigated
Limited impact with proper file upload restrictions and web application firewalls in place.
🎯 Exploit Status
Exploit chain involves two steps: removing .htaccess file then uploading malicious PHP file with space characters in filename.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.7
Vendor Advisory: https://github.com/jbroadway/elefant/releases/tag/elefant_2_0_7_stable
Restart Required: No
Instructions:
1. Backup your Elefant CMS installation. 2. Download Elefant CMS 2.0.7 or later. 3. Replace all files except user-uploaded content and configuration files. 4. Verify the patch by checking the version.
🔧 Temporary Workarounds
Disable filemanager upload functionality
linuxTemporarily disable or restrict access to the vulnerable filemanager upload endpoint.
mv apps/filemanager/upload apps/filemanager/upload.disabled
Implement strict file upload filtering
allAdd additional file type validation in web server configuration.
Add 'Deny from all' to .htaccess in upload directory
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block requests to /filemanager/api/rm/ and suspicious upload patterns.
- Restrict network access to Elefant CMS administration interface and implement strict file upload policies.
🔍 How to Verify
Check if Vulnerable:
Check if version is below 2.0.7 and if /apps/filemanager/upload/drop.php exists and is accessible.Check Version:
grep -r 'elefant_version' conf/config.php | grep -o '[0-9]\+\.[0-9]\+\.[0-9]\+'Verify Fix Applied:
Verify version is 2.0.7 or higher and test that PHP file uploads with spaces in filenames are properly rejected.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /filemanager/api/rm/.htaccess
- File uploads with .php followed by spaces in filename
- Unauthorized file deletion in upload directories
Network Indicators:
- POST requests to /apps/filemanager/upload/drop.php with suspicious filenames
- Sequential requests to remove .htaccess then upload files
SIEM Query:
source="web_logs" AND (uri_path="/filemanager/api/rm/.htaccess" OR (uri_path="/apps/filemanager/upload/drop.php" AND user_agent CONTAINS ".php "))🔗 References
- https://github.com/jbroadway/elefant/commit/49ba8cc24e9f009ce30d2c2eb9eefeb9be4ce1d0
- https://github.com/jbroadway/elefant/issues/287
- https://github.com/jbroadway/elefant/releases/tag/elefant_2_0_7_stable
- https://github.com/jbroadway/elefant/commit/49ba8cc24e9f009ce30d2c2eb9eefeb9be4ce1d0
- https://github.com/jbroadway/elefant/issues/287
- https://github.com/jbroadway/elefant/releases/tag/elefant_2_0_7_stable
