CVE-2021-41450
📋 TL;DR
CVE-2021-41450 is an HTTP request smuggling vulnerability in TP-Link Archer AX10 v1 routers that allows remote attackers to send specially crafted HTTP packets to cause a denial-of-service (DoS) condition. This affects the web management interface of the router, potentially making it inaccessible. The attack requires no authentication and affects all users of vulnerable TP-Link AX10v1 routers.
💻 Affected Systems
- TP-Link Archer AX10 v1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete unavailability of the router's web management interface, requiring physical reset and potential service disruption for all connected devices.
Likely Case
Temporary DoS of the web interface preventing administrative access until router restart.
If Mitigated
No impact if patched or if web interface is disabled/not exposed to untrusted networks.
🎯 Exploit Status
HTTP request smuggling attacks are well-understood and tools exist for testing. The specific packet format may require some reverse engineering.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1_211117 or later
Vendor Advisory: https://www.tp-link.com/us/support/download/archer-ax10/v1/#Firmware
Restart Required: Yes
Instructions:
1. Download firmware v1_211117 or later from TP-Link support site. 2. Log into router web interface. 3. Navigate to System Tools > Firmware Upgrade. 4. Upload the firmware file. 5. Wait for automatic reboot (do not interrupt power).
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to web management interface
Log into router > Advanced > System Tools > Administration > Disable 'Remote Management'
Restrict Web Interface Access
allLimit web interface access to trusted IPs only
Log into router > Advanced > Security > Access Control > Set IP/MAC Binding or Firewall rules
🧯 If You Can't Patch
- Disable the web management interface entirely if not needed
- Place router behind a firewall that filters abnormal HTTP requests
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System Tools > Firmware Upgrade. If version is earlier than v1_211117, device is vulnerable.Check Version:
No CLI command - must check via web interface at 192.168.0.1 or 192.168.1.1Verify Fix Applied:
After updating, verify firmware version shows v1_211117 or later in the same location.📡 Detection & Monitoring
Log Indicators:
- Multiple HTTP 400/500 errors from router web interface
- Unusual HTTP request patterns with conflicting headers
Network Indicators:
- Abnormal HTTP packets targeting router management port (typically 80/443)
- HTTP requests with conflicting Content-Length and Transfer-Encoding headers
SIEM Query:
source_ip="router_ip" AND (http_status>=400 OR http_method="POST" WITH abnormal_headers)