CVE-2017-14127
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary operating system commands with root privileges on Technicolor TD5336 routers. Attackers can inject shell commands through the pingAddr parameter in the web interface's ping module. This affects Technicolor TD5336 devices running OI_Fw_v7 firmware.
💻 Affected Systems
- Technicolor TD5336
📦 What is this software?
Td5336 Firmware by Technicolor
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router with root access, allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and brick the device.
Likely Case
Remote code execution leading to network compromise, credential theft, DNS hijacking, and creation of botnet nodes.
If Mitigated
Limited impact if device is behind firewall with restricted web interface access and proper network segmentation.
🎯 Exploit Status
Exploit is simple and requires no authentication. Public proof-of-concept exists in the referenced blog post.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available from Technicolor. Consider replacing affected devices or implementing workarounds.
🔧 Temporary Workarounds
Disable Web Interface Remote Access
allDisable remote administration/access to the router's web interface from WAN/internet.
Access router admin panel -> Security -> Remote Management -> Disable
Block Access to mnt_ping.cgi
linuxUse firewall rules to block access to the vulnerable endpoint.
iptables -A INPUT -p tcp --dport 80 -m string --string "mnt_ping.cgi" --algo bm -j DROP
🧯 If You Can't Patch
- Replace affected Technicolor TD5336 routers with newer models from different vendors
- Place router behind additional firewall with strict inbound rules blocking web interface ports
🔍 How to Verify
Check if Vulnerable:
Access router web interface, navigate to ping diagnostic page, attempt command injection in ping address field with payload like '; ls #'Check Version:
Check firmware version in router admin panel under System Status or About pageVerify Fix Applied:
Test if command injection no longer works after implementing workarounds. Verify web interface is not accessible from WAN.📡 Detection & Monitoring
Log Indicators:
- Unusual ping requests with special characters
- Multiple failed login attempts followed by ping requests
- Log entries showing command execution
Network Indicators:
- HTTP POST requests to /mnt_ping.cgi with shell metacharacters in parameters
- Unusual outbound connections from router
SIEM Query:
source="router.log" AND ("mnt_ping.cgi" AND ("|" OR ";" OR "`" OR "$"))