CVE-2021-46586
📋 TL;DR
This is a buffer overflow vulnerability in Bentley MicroStation CONNECT that allows remote code execution when users open malicious 3DS files. Attackers can exploit this to run arbitrary code with the privileges of the current user. Users of affected Bentley MicroStation versions are at risk.
💻 Affected Systems
- Bentley MicroStation CONNECT
📦 What is this software?
View by Bentley
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the affected system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation leading to malware installation, data exfiltration, or persistence mechanisms being established on the compromised system.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially resulting in application crash but no code execution.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). The vulnerability is well-documented and weaponization is likely given the RCE potential.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 10.16.1.0 or later
Vendor Advisory: https://www.bentley.com/en/common-vulnerability-exposure/BE-2021-0004
Restart Required: Yes
Instructions:
1. Download the latest version from Bentley's official website. 2. Run the installer. 3. Follow installation prompts. 4. Restart the system after installation completes.
🔧 Temporary Workarounds
Disable 3DS file association
windowsRemove file type association for .3ds files to prevent automatic opening in MicroStation
Windows: Use 'Default Apps' settings to change .3ds file association to another program or 'Ask every time'
Application control policy
allImplement application whitelisting to prevent execution of unauthorized code
🧯 If You Can't Patch
- Implement strict file validation policies to block suspicious 3DS files at network perimeter
- Use application sandboxing or virtualization to isolate MicroStation from critical systems
🔍 How to Verify
Check if Vulnerable:
Check MicroStation version: Open MicroStation → Help → About → Version informationCheck Version:
On Windows: Check program properties or registry at HKEY_LOCAL_MACHINE\SOFTWARE\Bentley\MicroStationVerify Fix Applied:
Verify version is 10.16.1.0 or later in About dialog📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected child processes spawned from MicroStation
- Unusual file access patterns for .3ds files
Network Indicators:
- Downloads of 3DS files from untrusted sources
- Outbound connections from MicroStation process to unknown IPs
SIEM Query:
Process creation where parent_process contains 'MicroStation' AND (process_name contains 'cmd' OR process_name contains 'powershell' OR process_name contains 'wscript')