CVE-2021-34941
📋 TL;DR
CVE-2021-34941 is a stack-based buffer overflow vulnerability in Bentley View's JT file parser that allows remote code execution. Attackers can exploit this by tricking users into opening malicious JT files or visiting malicious web pages. Users of affected Bentley View versions are at risk.
💻 Affected Systems
- Bentley View
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining the same privileges as the current user, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Local privilege escalation or malware installation on the victim's system, potentially leading to data exfiltration or persistence.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially only application crash.
🎯 Exploit Status
Exploitation requires user interaction but is technically straightforward once malicious file is opened.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.16.0.61 and later
Vendor Advisory: https://www.bentley.com/en/common-vulnerability-exposure/BE-2021-0005
Restart Required: Yes
Instructions:
1. Download latest Bentley View from official Bentley website. 2. Run installer. 3. Restart system after installation completes.
🔧 Temporary Workarounds
Disable JT file association
windowsRemove file type association for .jt files to prevent automatic opening in Bentley View
Control Panel > Default Programs > Associate a file type or protocol with a program > Select .jt > Change program > Choose different application
Application sandboxing
windowsRun Bentley View in restricted environment or sandbox
🧯 If You Can't Patch
- Implement strict file type filtering at email gateways and web proxies to block .jt files
- Educate users to never open JT files from untrusted sources and implement application whitelisting
🔍 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 10.16.0.61 or later in Help > About dialog.📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected process creation from Bentley View
- Abnormal network connections from Bentley View process
Network Indicators:
- Downloads of .jt files from suspicious sources
- Outbound connections from Bentley View to unknown IPs
SIEM Query:
process_name:"Bentley View" AND (event_type:crash OR parent_process:unexpected)