CVE-2021-34885
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code by tricking users into opening malicious JT files in Bentley View. The flaw exists in JT file parsing where crafted data can trigger a buffer over-read, potentially leading to code execution in the current process context. 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 via remote code execution, allowing attacker to install malware, steal data, or pivot to other systems.
Likely Case
Malware installation or data theft when users open malicious JT files from untrusted sources.
If Mitigated
Limited impact if users only open trusted files and application runs with minimal privileges.
🎯 Exploit Status
Exploitation requires user interaction but is technically straightforward once malicious JT file is crafted.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.16.0.80 or 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. Install update. 3. Restart system. 4. Verify version is 10.16.0.80 or higher.
🔧 Temporary Workarounds
Disable JT file association
windowsRemove Bentley View as default handler for .jt files to prevent automatic opening
Windows: Control Panel > Default Programs > Set Associations > Remove .jt association with Bentley View
Application sandboxing
allRun Bentley View with restricted privileges using application control or sandboxing
🧯 If You Can't Patch
- Implement strict file validation policies to block untrusted JT files
- Use application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Bentley View version in Help > About. If version is 10.15.0.75 or earlier, system is vulnerable.Check Version:
Windows: wmic product where name="Bentley View" get versionVerify Fix Applied:
Verify version is 10.16.0.80 or later in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes when opening JT files
- Unusual process creation from Bentley View
Network Indicators:
- Downloads of JT files from untrusted sources
- Outbound connections from Bentley View to unknown IPs
SIEM Query:
process_name:"Bentley View" AND (event_type:crash OR parent_process:explorer.exe AND child_process:cmd.exe)