CVE-2019-9750
📋 TL;DR
This vulnerability in IoTivity allows attackers to perform Distributed Denial of Service (DDoS) attacks using UDP traffic amplification. Attackers can spoof source IP addresses to send small requests that trigger responses 6 times larger, overwhelming target systems. This affects all systems running vulnerable IoTivity versions with CoAP server interfaces exposed.
💻 Affected Systems
- IoTivity
📦 What is this software?
Iotivity by Iotivity
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption through amplified DDoS attacks, potentially taking down critical IoT infrastructure and causing cascading failures in dependent systems.
Likely Case
Intermittent service degradation or outages for IoT devices and services using vulnerable IoTivity implementations, particularly affecting internet-facing deployments.
If Mitigated
Minimal impact if proper network controls are in place to limit UDP traffic and filter spoofed IP addresses.
🎯 Exploit Status
Attack requires UDP access to CoAP server interface. Amplification factor of 6x makes this attractive for DDoS attacks.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: https://jira.iotivity.org/browse/IOT-3267
Restart Required: No
Instructions:
No official patch available. Vendor states they are migrating to IoTivity Lite instead of fixing this version.
🔧 Temporary Workarounds
Network ACLs for CoAP
linuxRestrict UDP access to CoAP server interfaces (default port 5683) using firewall rules
iptables -A INPUT -p udp --dport 5683 -j DROP
ufw deny 5683/udp
BCP38 Implementation
allImplement BCP38/BCP84 to prevent IP address spoofing at network perimeter
🧯 If You Can't Patch
- Migrate to IoTivity Lite as recommended by vendor
- Implement rate limiting on UDP traffic to CoAP interfaces
- Deploy DDoS protection services
- Isolate vulnerable systems in separate network segments
🔍 How to Verify
Check if Vulnerable:
Check IoTivity version and verify CoAP server interface is enabled. Test with UDP traffic to port 5683.Check Version:
iotivity --version or check package manager (apt list --installed | grep iotivity)Verify Fix Applied:
Verify migration to IoTivity Lite or implementation of network controls. Test that UDP amplification no longer occurs.📡 Detection & Monitoring
Log Indicators:
- Unusual UDP traffic spikes on port 5683
- Multiple '4.01 Unauthorized' responses from CoAP server
- Network interface saturation alerts
Network Indicators:
- UDP traffic amplification patterns (6:1 ratio)
- Spoofed source IP addresses in CoAP requests
- High volume of CoAP responses from single source
SIEM Query:
source_port=5683 AND protocol=UDP AND bytes_out > (bytes_in * 5)