CVE-2021-33549
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected IP cameras via a stack-based buffer overflow in the action parameter. It affects multiple vendors including UDP Technology and Geutebrück. Attackers can potentially take full control of vulnerable devices.
💻 Affected Systems
- UDP Technology IP cameras
- Geutebrück IP cameras
- Other rebranded devices using affected firmware
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network pivoting, and disruption of surveillance operations.
Likely Case
Remote code execution allowing camera manipulation, data exfiltration, or use as botnet nodes.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation.
🎯 Exploit Status
Public exploit code available on Packet Storm and other sources. Exploitation requires sending crafted HTTP requests to 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. Check vendor website for firmware updates. 2. Download latest firmware. 3. Upload via camera web interface. 4. Reboot camera. 5. Verify update applied.
🔧 Temporary Workarounds
Network Segmentation
allIsolate cameras on separate VLAN with strict firewall rules
Access Control
allRestrict web interface access to trusted IP addresses only
🧯 If You Can't Patch
- Disable camera web interface if not required
- Implement network-based intrusion detection for exploit patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version against vendor advisories or test with non-destructive exploit PoCCheck Version:
Check camera web interface > System > Firmware or similar menuVerify Fix Applied:
Verify firmware version is updated beyond vulnerable versions listed in advisories📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to action parameter
- Multiple failed exploit attempts
- Unexpected process execution
Network Indicators:
- HTTP requests with long action parameters
- Exploit pattern matches from public PoCs
SIEM Query:
http.url:*action* AND (http.user_agent:curl OR http.request_length>1000)🔗 References
- http://packetstormsecurity.com/files/164191/Geutebruck-instantrec-Remote-Command-Execution.html
- https://us-cert.cisa.gov/ics/advisories/icsa-21-208-03
- https://www.randorisec.fr/fr/udp-technology-ip-camera-vulnerabilities/
- http://packetstormsecurity.com/files/164191/Geutebruck-instantrec-Remote-Command-Execution.html
- https://us-cert.cisa.gov/ics/advisories/icsa-21-208-03
- https://www.randorisec.fr/fr/udp-technology-ip-camera-vulnerabilities/
