CVE-2023-27078
📋 TL;DR
This CVE describes a command injection vulnerability in TP-Link MR3020 routers that allows remote attackers to execute arbitrary commands via crafted requests to the TFTP endpoint. Attackers can gain full control of affected devices without authentication. Only TP-Link MR3020 routers running specific vulnerable firmware versions are affected.
💻 Affected Systems
- TP-Link MR3020 portable 3G/4G wireless router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, intercept network traffic, pivot to internal networks, or use the device for botnet activities.
Likely Case
Remote code execution leading to device takeover, credential theft, and network surveillance capabilities.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details are available in GitHub repositories, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official TP-Link advisory found at time of analysis
Restart Required: No
Instructions:
1. Check TP-Link support site for firmware updates
2. If update available, download from official TP-Link website
3. Access router admin interface
4. Navigate to System Tools > Firmware Upgrade
5. Upload and apply new firmware
6. Verify successful update
🔧 Temporary Workarounds
Disable TFTP Service
allDisable the TFTP service if not required for operations
Access router admin interface and disable TFTP/Trivial File Transfer Protocol service
Network Access Control
allRestrict access to router management interfaces
Configure firewall rules to block inbound access to port 69 (TFTP) and router admin ports
🧯 If You Can't Patch
- Isolate affected devices in separate network segments with strict firewall rules
- Implement network monitoring for suspicious TFTP traffic and command execution attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface (System Tools > Firmware Upgrade) and compare to vulnerable version 1_150921Check Version:
Access router web interface or check via telnet/ssh if enabled: cat /proc/version or show version commandsVerify Fix Applied:
Verify firmware version has been updated to a version later than 1_150921📡 Detection & Monitoring
Log Indicators:
- Unusual TFTP requests
- Command execution attempts in system logs
- Unexpected process creation
Network Indicators:
- TFTP traffic to router on port 69 with unusual payloads
- Outbound connections from router to suspicious IPs
SIEM Query:
source_ip="router_ip" AND (port=69 OR protocol="tftp") AND payload_contains="$" OR payload_contains="|" OR payload_contains="`"