CVE-2025-53711
📋 TL;DR
A buffer overflow vulnerability in TP-Link TL-WR841N V11 routers allows remote attackers to crash the web service by sending specially crafted requests to the /userRpm/WlanNetworkRpm.htm endpoint, causing denial-of-service. This affects users of TP-Link TL-WR841N V11 routers that are exposed to network access. The vulnerability is particularly concerning because these products are no longer supported by the manufacturer.
💻 Affected Systems
- TP-Link TL-WR841N
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete denial-of-service rendering the router's web interface inaccessible, potentially requiring physical reset or power cycle to restore functionality.
Likely Case
Temporary web service crash causing loss of web-based management access until the service restarts or device reboots.
If Mitigated
No impact if the router's web interface is not exposed to untrusted networks or if traffic filtering prevents exploitation attempts.
🎯 Exploit Status
The vulnerability requires no authentication and can be triggered remotely via HTTP requests to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: https://www.tp-link.com/us/support/faq/4569/
Restart Required: No
Instructions:
No official patch is available as this product is end-of-life. Consider replacing with supported hardware.
🔧 Temporary Workarounds
Disable Remote Web Management
allPrevent external access to the router's web interface by disabling remote management features.
Access router web interface > Security > Remote Management > Disable
Network Segmentation
allIsolate vulnerable routers on separate network segments with firewall rules blocking access to web management ports.
🧯 If You Can't Patch
- Replace affected routers with supported models that receive security updates
- Implement network-level protections such as WAF or IPS to block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check router model and version via web interface (Status > Router) or physical label. If TL-WR841N V11, assume vulnerable.Check Version:
N/A - Check via web interface or physical device labelVerify Fix Applied:
No fix available to verify. Workarounds can be verified by testing web interface accessibility from restricted networks.📡 Detection & Monitoring
Log Indicators:
- Multiple HTTP requests to /userRpm/WlanNetworkRpm.htm with abnormal parameters
- Web service crash/restart logs
Network Indicators:
- HTTP traffic to router IP on port 80/443 targeting the vulnerable endpoint with crafted parameters
SIEM Query:
source_ip="*" AND dest_port IN (80, 443) AND url_path="/userRpm/WlanNetworkRpm.htm" AND (param_length>normal OR contains_special_chars)