CVE-2021-34911
📋 TL;DR
CVE-2021-34911 is a use-after-free vulnerability in Bentley View's 3DS file parser that allows remote code execution when users open malicious 3DS files or visit malicious web pages. This affects Bentley View users running vulnerable versions, potentially allowing attackers to execute arbitrary code with the privileges of the current user.
💻 Affected Systems
- Bentley View
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via arbitrary code execution with user privileges, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Malware installation or data exfiltration when users open malicious 3DS files from untrusted sources.
If Mitigated
Limited impact if proper application whitelisting, file type restrictions, and user awareness training are implemented.
🎯 Exploit Status
Exploitation requires user interaction but is straightforward once malicious file is opened. ZDI-CAN-14884 indicates professional vulnerability research.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Bentley View 10.16.0.80 or later
Vendor Advisory: https://www.bentley.com/en/common-vulnerability-exposure/BE-2021-0004
Restart Required: Yes
Instructions:
1. Download latest Bentley View from official Bentley website. 2. Install the update. 3. Restart the application and system if prompted.
🔧 Temporary Workarounds
Disable 3DS file association
windowsRemove Bentley View as default handler for .3ds files
Control Panel > Default Programs > Set Associations > Find .3ds > Change program to Notepad or other safe viewer
Application control policy
allBlock execution of Bentley View via application whitelisting
🧯 If You Can't Patch
- Implement strict email filtering to block .3ds attachments
- Educate users to never open .3ds files from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Bentley View version via Help > About. If version is 10.15.0.75 or earlier, system is vulnerable.Check Version:
In Bentley View: Help > AboutVerify Fix Applied:
Verify version is 10.16.0.80 or later in Help > About dialog.📡 Detection & Monitoring
Log Indicators:
- Process creation events from Bentley View with suspicious child processes
- File access to .3ds files followed by unusual network connections
Network Indicators:
- Outbound connections from Bentley View process to unknown IPs
- DNS requests for suspicious domains after .3ds file access
SIEM Query:
process_name:"Bentley View" AND (process_create OR network_connection)