CVE-2019-12150
📋 TL;DR
CVE-2019-12150 is an arbitrary file upload vulnerability in Karamasoft UltimateEditor 1 that allows attackers to upload any file type without restriction. This enables remote code execution by uploading malicious files like web shells. All systems running the vulnerable version are affected.
💻 Affected Systems
- Karamasoft UltimateEditor
📦 What is this software?
Ultimateeditor by Karamasoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via remote code execution, data theft, and lateral movement within the network.
Likely Case
Web shell deployment leading to data exfiltration, defacement, or further exploitation.
If Mitigated
Unauthorized file uploads blocked, preventing code execution but potentially allowing DoS via storage exhaustion.
🎯 Exploit Status
Simple file upload with no validation; exploit tools likely exist given public PoC.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.karamasoft.com
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if exists, or implement workarounds.
🔧 Temporary Workarounds
Implement File Upload Validation
allAdd server-side validation to restrict uploaded files to allowed types and extensions.
Modify upload handler code to check file MIME types and extensions before saving.
Restrict Access to Upload Directory
allBlock direct web access to the UltimateEditorInclude/UserFiles/ directory.
Add .htaccess (Apache) or web.config (IIS) rules to deny access to the upload directory.
🧯 If You Can't Patch
- Disable the Attach icon/upload functionality entirely in the editor configuration.
- Implement WAF rules to block requests containing suspicious file uploads to the vulnerable endpoint.
🔍 How to Verify
Check if Vulnerable:
Attempt to upload a non-image file (e.g., .php, .aspx) via the Attach icon and check if it's saved and accessible.Check Version:
Check software documentation or interface for version information; version 1 is vulnerable.Verify Fix Applied:
Test file upload with restricted types; only allowed files should be accepted and saved.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to upload endpoints with unusual file extensions or MIME types.
- File creation events in UltimateEditorInclude/UserFiles/ directory with executable extensions.
Network Indicators:
- Unusual outbound connections from the server post-upload, indicating potential shell activity.
SIEM Query:
source="web_server_logs" AND (uri_path="/UltimateEditorInclude/UserFiles/" OR method="POST" AND uri_path CONTAINS "upload") AND (file_extension IN ("php", "jsp", "aspx", "exe") OR user_agent CONTAINS "shell")