CVE-2021-33545
📋 TL;DR
This vulnerability affects multiple IP camera devices from UDP Technology, Geutebrück, and other vendors. It allows remote attackers to execute arbitrary code by exploiting a stack-based buffer overflow in the counter parameter. Organizations using these vulnerable camera models are at risk.
💻 Affected Systems
- UDP Technology IP cameras
- Geutebrück IP cameras
- Various rebranded IP cameras using UDP Technology firmware
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to gain persistent access, disable cameras, pivot to internal networks, or use cameras as botnet nodes.
Likely Case
Camera compromise leading to video feed interception, denial of service, or lateral movement within the network.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation attempts.
🎯 Exploit Status
Public exploit code exists. Attack requires sending specially crafted HTTP requests to the camera web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Vendor-specific firmware updates
Vendor Advisory: https://us-cert.cisa.gov/ics/advisories/icsa-21-208-03
Restart Required: Yes
Instructions:
1. Identify camera model and vendor. 2. Check vendor website for security advisories. 3. Download latest firmware. 4. Backup camera configuration. 5. Apply firmware update via web interface. 6. Verify update and restore configuration.
🔧 Temporary Workarounds
Network Segmentation
allIsolate cameras on separate VLAN with restricted access
Access Control Lists
allRestrict camera web interface access to authorized IPs only
🧯 If You Can't Patch
- Disable camera web interface if not required
- Implement strict firewall rules blocking all external access to camera management ports
🔍 How to Verify
Check if Vulnerable:
Check camera firmware version against vendor advisories. Test with authorized vulnerability scanner.Check Version:
Check camera web interface → System → Firmware/Version pageVerify Fix Applied:
Verify firmware version matches patched version from vendor. Test with vulnerability scanner to confirm fix.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to camera web interface
- Multiple failed authentication attempts
- Unexpected firmware version changes
Network Indicators:
- Unusual outbound connections from cameras
- HTTP requests with long counter parameters
- Traffic to known exploit IPs
SIEM Query:
source="camera_logs" AND (http_uri="*counter=*" OR status=500) | stats count by src_ip