CVE-2026-3431
📋 TL;DR
SimStudio versions below 0.5.74 have MongoDB tool endpoints that accept arbitrary connection parameters without authentication or host restrictions. This allows attackers to connect to any reachable MongoDB instance and perform unauthorized operations including data reading, modification, and deletion. Organizations using vulnerable SimStudio versions are affected.
💻 Affected Systems
- SimStudio
📦 What is this software?
Sim by Sim
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all MongoDB instances reachable from the vulnerable system, leading to data theft, destruction, or ransomware deployment across multiple databases.
Likely Case
Attackers exfiltrate sensitive data from accessible MongoDB instances, potentially including customer information, intellectual property, or credentials.
If Mitigated
Limited impact if MongoDB instances are properly secured with authentication, network segmentation, and access controls.
🎯 Exploit Status
Exploitation requires network access to SimStudio endpoints but no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.5.74
Vendor Advisory: https://www.tenable.com/security/research/tra-2026-12
Restart Required: Yes
Instructions:
1. Download SimStudio version 0.5.74 or higher from official sources. 2. Stop SimStudio service. 3. Install the updated version. 4. Restart SimStudio service.
🔧 Temporary Workarounds
Disable MongoDB tool endpoints
allTemporarily disable the vulnerable MongoDB tool endpoints in SimStudio configuration.
Edit SimStudio config file and set 'mongodb_tools_enabled: false'
Network segmentation
linuxRestrict network access to SimStudio MongoDB endpoints using firewall rules.
iptables -A INPUT -p tcp --dport [SimStudio_port] -j DROP
ufw deny [SimStudio_port]
🧯 If You Can't Patch
- Implement strict network segmentation to isolate SimStudio from MongoDB instances and other critical systems.
- Enable MongoDB authentication and IP whitelisting on all MongoDB instances to limit unauthorized access.
🔍 How to Verify
Check if Vulnerable:
Check SimStudio version via web interface or configuration file. If version is below 0.5.74, the system is vulnerable.Check Version:
Check SimStudio web interface or config file for version number.Verify Fix Applied:
Confirm SimStudio version is 0.5.74 or higher and test that MongoDB tool endpoints now require authentication.📡 Detection & Monitoring
Log Indicators:
- Unusual connection attempts to MongoDB tool endpoints
- Failed authentication attempts if authentication is enabled
Network Indicators:
- Unexpected outbound connections from SimStudio to MongoDB instances
- Traffic to MongoDB default port 27017 from SimStudio
SIEM Query:
source="SimStudio" AND (event="mongodb_connection" OR port=27017)