CVE-2018-15720
📋 TL;DR
Logitech Harmony Hub devices contained hard-coded XMPP accounts that allowed remote attackers to access the local API without authentication. This affects all Harmony Hub devices running firmware versions before 4.15.206, potentially allowing attackers to control connected smart home devices.
💻 Affected Systems
- Logitech Harmony Hub
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full control of the Harmony Hub and all connected smart home devices (lights, locks, thermostats, etc.), enabling physical security breaches, surveillance, or property damage.
Likely Case
Attackers access the Harmony Hub API to control entertainment systems and connected IoT devices, potentially enabling unauthorized surveillance or nuisance attacks.
If Mitigated
With proper network segmentation and firewall rules, impact is limited to entertainment system control without access to critical IoT devices.
🎯 Exploit Status
Exploitation requires only knowledge of the hard-coded credentials and basic XMPP protocol usage. Public exploit scripts are available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.15.206 and later
Vendor Advisory: https://support.logi.com/hc/en-us/articles/360025298573
Restart Required: Yes
Instructions:
1. Open Harmony app on mobile device. 2. Go to Menu > Harmony Setup > Add/Edit Devices & Activities > Remote & Hub. 3. Select your hub. 4. Tap 'Update' if available. 5. The hub will restart automatically after update.
🔧 Temporary Workarounds
Block XMPP Port
linuxBlock inbound XMPP connections to the Harmony Hub on port 5222
iptables -A INPUT -p tcp --dport 5222 -j DROP
Network Segmentation
allIsolate Harmony Hub on separate VLAN without internet access
🧯 If You Can't Patch
- Disable remote access in Harmony app settings to prevent internet exposure
- Place Harmony Hub behind firewall with strict inbound rules, blocking all external access to port 5222
🔍 How to Verify
Check if Vulnerable:
Check firmware version in Harmony app: Menu > Harmony Setup > Add/Edit Devices & Activities > Remote & Hub > select hub. If version is below 4.15.206, device is vulnerable.Check Version:
No CLI command available. Must use Harmony mobile app interface.Verify Fix Applied:
Verify firmware version is 4.15.206 or higher in the Harmony app. Attempt XMPP connection with hard-coded credentials should fail.📡 Detection & Monitoring
Log Indicators:
- XMPP authentication attempts with hard-coded usernames: 'guest' or 'alpha'
- Unusual API calls to Harmony Hub local endpoints
Network Indicators:
- XMPP traffic (port 5222) from unexpected external IPs
- API calls to Harmony Hub from unauthorized sources
SIEM Query:
source_port=5222 AND (username="guest" OR username="alpha")