CVE-2019-9121
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands with root privileges on affected Motorola C1 and M2 devices. Attackers can exploit it by sending a specially crafted POST request to the HNAP1 interface, enabling complete system compromise. Only users of Motorola C1 and M2 devices with specific vulnerable firmware versions are affected.
💻 Affected Systems
- Motorola C1
- Motorola M2
📦 What is this software?
C1 Firmware by Motorola
M2 Firmware by Motorola
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root shell access, allowing attackers to install persistent malware, steal credentials, pivot to internal networks, or brick devices.
Likely Case
Remote code execution leading to device takeover, network reconnaissance, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details available in GitHub repository. Simple HTTP POST request with crafted payload.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
Check Motorola support for firmware updates. If available, download and install latest firmware via device management interface.
🔧 Temporary Workarounds
Disable HNAP1 Interface
allDisable the HNAP1 web interface if not required for functionality.
Check device web interface for HNAP/UPnP settings and disable
Network Segmentation
allIsolate affected devices in separate VLAN with strict firewall rules.
🧯 If You Can't Patch
- Implement strict network access controls to block all inbound traffic to device management interfaces
- Monitor network traffic for suspicious HNAP1 POST requests with shell metacharacters
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface. If C1 firmware is 1.01 or M2 firmware is 1.07, device is vulnerable.Check Version:
Check via device web interface or SSH if available: cat /etc/versionVerify Fix Applied:
Verify firmware version has been updated to a version later than the vulnerable ones.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /HNAP1
- System logs showing unexpected command execution
- Failed authentication attempts to device
Network Indicators:
- HTTP POST requests to /HNAP1 containing shell metacharacters like ;, |, &, $()
- Unusual outbound connections from device
SIEM Query:
http.method:POST AND http.uri:"/HNAP1" AND (http.body:*;* OR http.body:*|* OR http.body:*&* OR http.body:*$(*))