CVE-2025-51736
📋 TL;DR
This CVE describes a file upload vulnerability in HCL Unica 12.0.0 that allows attackers to upload malicious files to the server. The vulnerability affects organizations using HCL Unica 12.0.0 and could lead to server compromise.
💻 Affected Systems
- HCL Unica
📦 What is this software?
Unica by Hcltech
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data exfiltration, and lateral movement within the network.
Likely Case
Malicious file upload leading to web shell deployment, data manipulation, or denial of service.
If Mitigated
Limited impact with proper file validation and access controls in place.
🎯 Exploit Status
The GitHub gist contains technical details that could be used to create an exploit. Authentication is typically required to access file upload functionality.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified
Vendor Advisory: Not available
Restart Required: No
Instructions:
1. Monitor HCL security advisories for official patch
2. Apply patch when available
3. Test in non-production environment first
🔧 Temporary Workarounds
Implement strict file upload validation
allConfigure the application to only accept specific file types and validate file content
Restrict upload directory permissions
linuxSet upload directories to read-only for web server and prevent execution of uploaded files
chmod 644 /path/to/upload/directory/*
chown root:root /path/to/upload/directory
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block malicious file uploads
- Disable file upload functionality entirely if not required
🔍 How to Verify
Check if Vulnerable:
Check if running HCL Unica 12.0.0 and review file upload functionality for proper validationCheck Version:
Check application version in admin console or configuration filesVerify Fix Applied:
Test file upload with malicious payloads after implementing controls📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads
- Large number of upload requests
- Uploads with suspicious file extensions
Network Indicators:
- HTTP POST requests to upload endpoints with unusual payloads
SIEM Query:
source="web_server" AND (method="POST" AND uri CONTAINS "upload") AND (file_extension="php" OR file_extension="jsp" OR file_extension="asp")