CVE-2025-25898
📋 TL;DR
A buffer overflow vulnerability in TP-Link TL-WR841ND V11 routers allows attackers to cause Denial of Service (DoS) by sending specially crafted packets to the pskSecret parameter. This affects users of TP-Link TL-WR841ND V11 routers with default configurations. Attackers can crash the device remotely without authentication.
💻 Affected Systems
- TP-Link TL-WR841ND
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical power cycle, potential for remote code execution if memory corruption can be controlled
Likely Case
Router becomes unresponsive, requiring reboot and causing temporary network outage
If Mitigated
No impact if device is patched or network segmentation prevents access
🎯 Exploit Status
Proof of concept available in GitHub repository, exploitation appears straightforward based on buffer overflow in pskSecret parameter
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check TP-Link for latest firmware
Vendor Advisory: https://www.tp-link.com/support/download/tl-wr841nd/v11/
Restart Required: Yes
Instructions:
1. Log into router admin interface 2. Navigate to System Tools > Firmware Upgrade 3. Download latest firmware from TP-Link website 4. Upload and install firmware 5. Router will reboot automatically
🔧 Temporary Workarounds
Disable remote management
router-web-interfacePrevent external access to router web interface
Navigate to Security > Remote Management > Disable
Network segmentation
network-infrastructureIsolate router management interface from untrusted networks
🧯 If You Can't Patch
- Replace vulnerable device with supported model
- Implement strict network ACLs to block access to router web interface from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System Tools > Firmware UpgradeCheck Version:
Check web interface or use nmap -sV to identify router versionVerify Fix Applied:
Verify firmware version matches latest available from TP-Link website📡 Detection & Monitoring
Log Indicators:
- Multiple failed connection attempts to /userRpm/WlanSecurityRpm.htm
- Router reboot events without user action
- Unusual POST requests with long pskSecret parameters
Network Indicators:
- HTTP traffic to router IP on port 80 with crafted pskSecret parameter
- Sudden loss of connectivity to router management interface
SIEM Query:
source="router-logs" AND (uri="/userRpm/WlanSecurityRpm.htm" AND content_length>1000)