CVE-2021-42118
📋 TL;DR
This vulnerability allows authenticated attackers with object modification privileges to inject malicious HTML/JavaScript into the TopEase® Platform's Structure Component. The injected code executes when other users view affected objects, enabling session hijacking through cookie theft. Organizations using Business-DNA Solutions GmbH's TopEase® Platform version 7.1.27 or earlier are affected.
💻 Affected Systems
- Business-DNA Solutions GmbH TopEase® Platform
📦 What is this software?
Topease by Businessdnasolutions
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover leading to administrative privilege escalation, data exfiltration, and further lateral movement within the platform.
Likely Case
Session hijacking of authenticated users, unauthorized access to sensitive business data, and potential manipulation of platform objects.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, though authenticated attackers could still cause minor disruptions.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once privileges are obtained; XSS payloads are well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: > 7.1.27
Vendor Advisory: https://confluence.topease.ch/confluence/display/DOC/Release+Notes
Restart Required: Yes
Instructions:
1. Upgrade TopEase® Platform to version newer than 7.1.27. 2. Apply vendor-provided patches. 3. Restart the TopEase® service. 4. Verify the fix by testing Structure Component input validation.
🔧 Temporary Workarounds
Implement Content Security Policy
allAdd CSP headers to restrict script execution and mitigate XSS impact
Add 'Content-Security-Policy: script-src 'self'' to web server configuration
Restrict Object Modification Privileges
allLimit users with object modification capabilities to trusted personnel only
Review and reduce user permissions in TopEase® administration panel
🧯 If You Can't Patch
- Implement strict input validation and output encoding for all user-controllable fields in Structure Component
- Deploy web application firewall with XSS protection rules and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check TopEase® version in administration panel or via platform interface; if version is 7.1.27 or earlier, system is vulnerable.Check Version:
Check TopEase® web interface administration section or consult platform documentation for version display.Verify Fix Applied:
After patching, attempt to inject basic XSS payloads into object attributes via Structure Component and verify they are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual object modification activity
- Multiple failed XSS attempts in web logs
- Suspicious JavaScript in object attribute fields
Network Indicators:
- Unexpected outbound connections following object access
- Patterns of cookie theft attempts
SIEM Query:
source="topease_logs" AND (event="object_modification" OR message="*script*" OR message="*javascript*")