CVE-2025-25897
📋 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 'ip' parameter in the web interface. This affects users of TP-Link TL-WR841ND V11 routers with default configurations.
💻 Affected Systems
- TP-Link TL-WR841ND
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reboot, potentially disrupting all network connectivity for connected devices.
Likely Case
Router becomes unresponsive, requiring manual reboot to restore functionality.
If Mitigated
Limited impact if network segmentation isolates the router from untrusted networks.
🎯 Exploit Status
Exploitation requires network access to the router's web interface and knowledge of the vulnerable parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Latest firmware from TP-Link for TL-WR841ND V11
Vendor Advisory: Check TP-Link security advisories
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to System Tools > Firmware Upgrade. 3. Download latest firmware from TP-Link support site. 4. Upload and apply firmware update. 5. Router will reboot automatically.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Navigate to Security > Remote Management and disable
Network Segmentation
allIsolate router management interface from untrusted networks
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the router's web interface
- Monitor router logs for unusual access patterns or repeated connection attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Tools > Firmware UpgradeCheck Version:
Check via web interface: System Tools > Firmware UpgradeVerify Fix Applied:
Verify firmware version matches latest available from TP-Link support site📡 Detection & Monitoring
Log Indicators:
- Multiple failed access attempts to /userRpm/WanStaticIpV6CfgRpm.htm
- Router reboot events without user action
Network Indicators:
- Unusual HTTP POST requests to router IP with crafted ip parameter
- Sudden loss of router responsiveness
SIEM Query:
source="router_logs" AND (uri="/userRpm/WanStaticIpV6CfgRpm.htm" OR event="reboot")