CVE-2021-34929
📋 TL;DR
CVE-2021-34929 is a buffer overflow vulnerability in Bentley View's JT file parser that allows remote code execution. Attackers can exploit it by tricking users into opening malicious JT files, potentially compromising affected systems. This affects Bentley View 10.15.0.75 users who process JT files.
💻 Affected Systems
- Bentley View
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the affected system, data theft, and lateral movement within the network.
Likely Case
Local privilege escalation leading to unauthorized access to sensitive engineering data and potential system disruption.
If Mitigated
Limited impact with proper file validation and user awareness preventing malicious file execution.
🎯 Exploit Status
Exploitation requires user interaction but is straightforward once malicious file is opened; weaponization likely due to available technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to Bentley View version 10.16.02 or later
Vendor Advisory: https://www.bentley.com/en/common-vulnerability-exposure/BE-2021-0005
Restart Required: Yes
Instructions:
1. Download latest Bentley View installer from Bentley website. 2. Run installer with administrative privileges. 3. Follow installation prompts. 4. Restart system after installation completes.
🔧 Temporary Workarounds
Disable JT file association
windowsPrevent Bentley View from automatically opening JT files by changing file associations
Control Panel > Default Programs > Associate a file type or protocol with a program > Change .jt association to Notepad or another safe viewer
Implement application whitelisting
windowsRestrict execution of Bentley View to trusted locations only
🧯 If You Can't Patch
- Implement strict file validation policies to block untrusted JT files
- Educate users about the risks of opening JT files from unknown sources
🔍 How to Verify
Check if Vulnerable:
Check Bentley View version in Help > About; if version is 10.15.0.75, system is vulnerable.Check Version:
wmic product where name="Bentley View" get versionVerify Fix Applied:
Verify version is 10.16.02 or later in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from Bentley View executable
- Multiple failed JT file parsing attempts in application logs
Network Indicators:
- Unexpected outbound connections from Bentley View process
- JT file downloads from untrusted sources
SIEM Query:
Process Creation where Image contains "Bentley View" and CommandLine contains ".jt"