CVE-2018-3856
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary operating system commands on Samsung SmartThings Hub STH-ETH-250 devices by exploiting improper handling of spaces in RTSP configuration URLs. Attackers can send specially crafted HTTP requests to achieve command injection, potentially gaining full control of affected devices. This affects users of the vulnerable firmware version.
💻 Affected Systems
- Samsung SmartThings Hub STH-ETH-250
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to install persistent malware, pivot to internal networks, disable security controls, or use device as part of botnet.
Likely Case
Attacker gains shell access to device, can modify configurations, steal credentials, or use device for further attacks.
If Mitigated
With proper network segmentation and access controls, impact limited to isolated device compromise without lateral movement.
🎯 Exploit Status
Exploitation requires sending HTTP requests to trigger the command injection via malformed URL parameters with spaces.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware versions after 0.20.17
Vendor Advisory: https://www.samsung.com/us/support/security/
Restart Required: Yes
Instructions:
1. Log into SmartThings Hub admin interface
2. Navigate to Settings > Firmware Update
3. Check for and apply available updates
4. Reboot device after update completes
🔧 Temporary Workarounds
Network Isolation
allPlace SmartThings Hub on isolated VLAN with restricted network access
Firewall Rules
linuxBlock external access to Hub management interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Disable RTSP functionality if not required
- Implement strict network segmentation to limit device communication
🔍 How to Verify
Check if Vulnerable:
Check firmware version via Hub admin interface or SSH if accessible. Version 0.20.17 is vulnerable.Check Version:
ssh admin@hub-ip 'cat /etc/version' or check via web interfaceVerify Fix Applied:
Confirm firmware version is updated beyond 0.20.17 and test RTSP configuration with spaces in URL field.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to RTSP configuration endpoints
- Commands with spaces in URL parameters
- Unexpected process execution
Network Indicators:
- HTTP POST/PUT requests to /rtsp/config with unusual parameters
- Outbound connections from Hub to unexpected destinations
SIEM Query:
source="smartthings-hub" AND (url="* *" OR method="POST" AND uri="/rtsp/config")