CVE-2021-28173
📋 TL;DR
CVE-2021-28173 is an unauthenticated remote code execution vulnerability in Vangene deltaFlow E-platform's file upload function. Attackers can upload and execute arbitrary files without authentication, potentially taking full control of affected systems. All organizations using vulnerable versions of this software are affected.
💻 Affected Systems
- Vangene deltaFlow E-platform
📦 What is this software?
Deltaflow by Deltaflow Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, steal sensitive data, deploy ransomware, or pivot to other network systems.
Likely Case
Attackers upload web shells or malware to gain persistent access, exfiltrate data, or use the system for further attacks.
If Mitigated
If proper access controls and file validation are implemented, attackers cannot upload malicious files or execute them.
🎯 Exploit Status
The vulnerability requires no authentication and involves simple file upload manipulation, making exploitation straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Specific version not publicly documented - contact vendor for patched version
Vendor Advisory: No public vendor advisory found - contact Vangene directly
Restart Required: Yes
Instructions:
1. Contact Vangene for the security patch. 2. Apply the patch to all affected systems. 3. Restart the deltaFlow E-platform service. 4. Verify the fix is working.
🔧 Temporary Workarounds
Disable file upload functionality
allTemporarily disable or restrict the vulnerable file upload feature until patching is possible
Configuration specific - modify application settings to disable file uploads
Implement web application firewall rules
allBlock malicious file upload attempts at the network perimeter
WAF specific - create rules to block suspicious file upload patterns
🧯 If You Can't Patch
- Isolate affected systems from internet access and restrict internal network access
- Implement strict file upload validation including file type checking, size limits, and content inspection
🔍 How to Verify
Check if Vulnerable:
Test if unauthenticated file upload is possible by attempting to upload a file without login credentialsCheck Version:
Check application version through admin interface or contact vendorVerify Fix Applied:
Attempt unauthenticated file upload after patching - it should be blocked or require authentication📡 Detection & Monitoring
Log Indicators:
- Unusual file upload activity from unauthenticated users
- Execution of unexpected files or processes
- Web shell deployment attempts
Network Indicators:
- Unusual outbound connections from the deltaFlow server
- File upload requests without authentication headers
SIEM Query:
source="deltaflow" AND (event="file_upload" AND user="anonymous") OR (process_execution="suspicious_file")