CVE-2021-34917
📋 TL;DR
CVE-2021-34917 is a use-after-free vulnerability in Bentley View's J2K file parser that allows remote code execution when a user opens a malicious J2K file or visits a malicious webpage. Attackers can exploit this to execute arbitrary code with the privileges of the current user. This affects users of Bentley View 10.15.0.75 who open untrusted J2K files.
💻 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 J2K files from untrusted sources.
If Mitigated
Limited impact if proper application whitelisting and file validation controls prevent execution of malicious files.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file) but is straightforward once the file is opened. ZDI-CAN-14895 tracking suggests active research interest.
🛠️ 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-2021-0006
Restart Required: Yes
Instructions:
1. Download latest Bentley View installer from official Bentley website. 2. Run installer with administrative privileges. 3. Follow installation prompts. 4. Restart system after installation completes.
🔧 Temporary Workarounds
Disable J2K file association
windowsRemove Bentley View as default handler for .j2k/.jp2 files to prevent automatic opening
Control Panel > Default Programs > Associate a file type or protocol with a program > Select .j2k/.jp2 > Change program to Notepad or other safe viewer
Application control policy
allBlock execution of Bentley View via application whitelisting/control solutions
🧯 If You Can't Patch
- Implement network segmentation to isolate Bentley View systems 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 or earlier, system is vulnerable.Check Version:
In Bentley View: Help > AboutVerify Fix Applied:
Verify Bentley View version is 10.16.02 or later via Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Process creation events from Bentley View with unusual command-line arguments
- Crash reports from Bentley View application
Network Indicators:
- Outbound connections from Bentley View process to unknown external IPs
- DNS requests for suspicious domains from Bentley View process
SIEM Query:
ProcessName="BentleyView.exe" AND (CommandLine CONTAINS ".j2k" OR CommandLine CONTAINS ".jp2") AND ParentProcess NOT IN ("explorer.exe", "cmd.exe")