CVE-2021-34903
📋 TL;DR
CVE-2021-34903 is a buffer overflow vulnerability in Bentley View's BMP file parser that allows remote code execution. Attackers can exploit it by tricking users into opening malicious BMP files or visiting malicious web pages. This affects Bentley View 10.15.0.75 users who process untrusted BMP 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
Attacker executes arbitrary code in the context of the current user, potentially installing malware, stealing sensitive data, or using the system as a foothold for further attacks.
If Mitigated
Limited impact with proper security controls - potentially application crash or denial of service if exploit fails, but no code execution.
🎯 Exploit Status
Exploitation requires user interaction but is technically straightforward once malicious file is opened. ZDI-CAN-14876 reference suggests detailed analysis exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to Bentley View version after 10.15.0.75
Vendor Advisory: https://www.bentley.com/en/common-vulnerability-exposure/BE-2021-0002
Restart Required: Yes
Instructions:
1. Download latest Bentley View version from official Bentley website. 2. Run installer with administrative privileges. 3. Restart system after installation completes.
🔧 Temporary Workarounds
Disable BMP file association
windowsRemove Bentley View as default handler for .bmp files to prevent automatic exploitation
Control Panel > Default Programs > Set Associations > Find .bmp > Change to another program
Application control policy
windowsBlock execution of Bentley View from untrusted locations or network shares
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized code execution
- Use network segmentation to isolate Bentley View systems from critical assets
🔍 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:
Not applicable - check via GUI Help > About menuVerify Fix Applied:
Verify version is updated beyond 10.15.0.75 in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes from Bentley View
- Unusual process creation from Bentley View executable
- Multiple failed attempts to open corrupted BMP files
Network Indicators:
- Downloads of BMP files from untrusted sources
- Outbound connections from Bentley View to suspicious IPs
SIEM Query:
Process Creation where Image contains 'Bentley View' AND Parent Process not in (explorer.exe, cmd.exe)