CVE-2021-37911
📋 TL;DR
This vulnerability allows attackers on the same local network to bypass privilege controls in BenQ smart wireless conference projector management interfaces. Attackers can access any system directory and execute arbitrary commands, potentially taking full control of affected devices. Organizations using these projectors on internal networks are affected.
💻 Affected Systems
- BenQ smart wireless conference projectors
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of projector with persistent backdoor installation, credential theft, and lateral movement to other network devices.
Likely Case
Unauthorized access to sensitive presentation materials, device configuration tampering, and use as pivot point for network attacks.
If Mitigated
Limited to isolated network segments with no critical systems accessible.
🎯 Exploit Status
Exploitation requires local network access but no authentication
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in provided references
Vendor Advisory: https://www.twcert.org.tw/tw/cp-132-5047-7ef35-1.html
Restart Required: Yes
Instructions:
1. Contact BenQ support for firmware updates. 2. Download latest firmware from vendor portal. 3. Apply update via management interface. 4. Verify update completion and restart device.
🔧 Temporary Workarounds
Network segmentation
allIsolate projectors on separate VLAN without access to critical systems
Management interface restriction
allDisable or restrict management interface to specific administrative IPs
🧯 If You Can't Patch
- Physically disconnect from network when not in use
- Implement strict firewall rules blocking all unnecessary traffic to projector
🔍 How to Verify
Check if Vulnerable:
Check if management interface is accessible from local network without authentication and test directory traversalCheck Version:
Check device web interface or serial console for firmware versionVerify Fix Applied:
Verify firmware version matches patched release and test that directory traversal no longer works📡 Detection & Monitoring
Log Indicators:
- Unusual access to management interface
- Multiple failed authentication attempts followed by successful access
- Commands executed via web interface
Network Indicators:
- Unusual outbound connections from projector
- Traffic to unexpected ports from projector IP
SIEM Query:
source_ip="projector_ip" AND (url_path CONTAINS "/cgi-bin/" OR url_path CONTAINS "system" OR method="POST" to management interface)