CVE-2021-34874
📋 TL;DR
CVE-2021-34874 is a memory corruption vulnerability in Bentley View that allows remote code execution when processing malicious 3DS files. Attackers can exploit this by tricking users into opening specially crafted files or visiting malicious web pages. This affects users of Bentley View 10.15.0.75 who open untrusted 3DS 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, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation or arbitrary code execution in the context of the current user, allowing attackers to steal sensitive data, install malware, or pivot to other systems.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially resulting in application crash but no system compromise.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). The vulnerability was discovered by Zero Day Initiative (ZDI-CAN-14736) and weaponization is likely given the RCE nature.
🛠️ 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-2021-0004
Restart Required: Yes
Instructions:
1. Download the latest version of Bentley View from Bentley's official website. 2. Run the installer and follow the upgrade process. 3. Restart the system to ensure all components are properly updated.
🔧 Temporary Workarounds
Disable 3DS file association
windowsRemove Bentley View as the default handler for .3ds files to prevent automatic exploitation
Control Panel > Default Programs > Associate a file type or protocol with a program > Select .3ds > Change program > Choose another application
Application control policy
windowsImplement application whitelisting to prevent execution of untrusted Bentley View files
🧯 If You Can't Patch
- Implement network segmentation to isolate systems running Bentley View from critical assets
- Deploy endpoint detection and response (EDR) solutions to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Bentley View version via Help > About. If version is 10.15.0.75, the system is vulnerable.Check Version:
In Bentley View: Help > About or check program properties in WindowsVerify Fix Applied:
Verify Bentley View version is 10.16.02 or later via Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes of Bentley View with memory access violations
- Unusual process creation from Bentley View executable
- Failed attempts to load 3DS files
Network Indicators:
- Downloads of 3DS files from untrusted sources
- Outbound connections from Bentley View to suspicious IPs
SIEM Query:
Process Creation where Image contains 'BentleyView.exe' AND CommandLine contains '.3ds'