CVE-2020-18462
📋 TL;DR
AikCms v2.0.0 contains an unauthenticated file upload vulnerability in poster_edit.php that allows attackers to upload arbitrary files without validation. This affects all systems running the vulnerable version of AikCms, potentially leading to remote code execution.
💻 Affected Systems
- AikCms
📦 What is this software?
Aikcms by Aikcms
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Webshell deployment allowing persistent access, data exfiltration, and further exploitation of the server.
If Mitigated
File upload attempts blocked or quarantined with no successful exploitation.
🎯 Exploit Status
Simple file upload exploitation with publicly available proof-of-concept.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available or implementing workarounds.
🔧 Temporary Workarounds
Implement File Upload Validation
allAdd server-side validation to restrict file types, extensions, and content.
Modify poster_edit.php to include file type validation (e.g., check MIME types, extensions like .jpg, .png only)
Disable Vulnerable Endpoint
allRemove or restrict access to poster_edit.php if not needed.
Rename or delete poster_edit.php file
Add .htaccess rules to block access to poster_edit.php
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block malicious file uploads.
- Restrict network access to the AikCms instance using firewall rules.
🔍 How to Verify
Check if Vulnerable:
Attempt to upload a file with a malicious extension (e.g., .php) to poster_edit.php endpoint.Check Version:
Check AikCms version in admin panel or configuration files.Verify Fix Applied:
Test file upload with restricted extensions; malicious uploads should be rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to poster_edit.php
- Files with suspicious extensions (.php, .exe) in upload directories
Network Indicators:
- HTTP POST requests to poster_edit.php with file uploads
SIEM Query:
source="web_logs" AND uri="/poster_edit.php" AND method="POST" AND file_upload="true"