CVE-2024-57049
📋 TL;DR
This vulnerability allows attackers to bypass authentication on TP-Link Archer C20 routers by adding a specific Referer header to requests targeting interfaces in the /cgi directory. This affects users of TP-Link Archer C20 routers with firmware version V6.6_230412 and earlier. The vendor disputes the severity, claiming only non-sensitive UI variables are exposed.
💻 Affected Systems
- TP-Link Archer C20 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing configuration changes, network traffic interception, malware deployment, and lateral movement to connected devices.
Likely Case
Unauthorized access to router administration interfaces, potential configuration changes, and exposure of network information.
If Mitigated
Limited exposure of non-sensitive UI initialization variables as claimed by vendor, with no critical system access.
🎯 Exploit Status
Simple HTTP request manipulation with Referer header, documented in public GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
Check TP-Link support for firmware updates. If available: 1. Download latest firmware from TP-Link website. 2. Log into router admin interface. 3. Navigate to System Tools > Firmware Upgrade. 4. Upload and apply new firmware.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router administration interface
Change Default Admin Credentials
allUse strong unique credentials for router administration
🧯 If You Can't Patch
- Segment network to isolate router management interface
- Implement network monitoring for suspicious authentication bypass attempts
🔍 How to Verify
Check if Vulnerable:
Send HTTP request to router /cgi interface with Referer: http://tplinkwifi.net header and check if authentication is bypassed.Check Version:
Log into router web interface and check firmware version in System Tools > Firmware Upgrade section.Verify Fix Applied:
Test same request after firmware update - authentication bypass should fail.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /cgi paths with Referer: http://tplinkwifi.net header
- Authentication failures followed by successful access
Network Indicators:
- Unusual HTTP traffic to router administration port (typically 80/443)
- Requests with manipulated Referer headers
SIEM Query:
source="router_logs" AND (uri="/cgi/*" AND referer="http://tplinkwifi.net")