CVE-2025-7505
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda FH451 routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the /goform/L7Prot endpoint. This affects Tenda FH451 routers running firmware version 1.0.0.9. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda FH451
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, lateral movement to internal networks, persistent backdoor installation, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept network traffic, or use the device as a pivot point for further attacks.
If Mitigated
Denial of service or temporary disruption if exploit attempts are blocked by network controls, though RCE remains possible if payloads reach the device.
🎯 Exploit Status
Public exploit code is available in GitHub repositories, making this easily weaponizable by attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None found in provided references
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. Download the latest firmware for FH451. 3. Log into router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install the new firmware. 6. Reboot the router.
🔧 Temporary Workarounds
Block External Access to Management Interface
linuxPrevent external access to the router's web management interface to block remote exploitation attempts.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Remote Management
allTurn off remote management feature in router settings to prevent external HTTP access.
🧯 If You Can't Patch
- Isolate affected routers in a separate VLAN with strict network segmentation
- Implement network-based intrusion prevention rules to block exploitation attempts targeting /goform/L7Prot
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface (System Status > Firmware Version) or via SSH if available. Version 1.0.0.9 is vulnerable.Check Version:
curl -s http://router-ip/goform/getStatus | grep version or check web interfaceVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.9. Test that /goform/L7Prot endpoint no longer accepts malformed POST requests.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/L7Prot with unusually long 'page' parameter values
- Router logs showing buffer overflow errors or unexpected reboots
Network Indicators:
- HTTP traffic to router IP on port 80/443 containing /goform/L7Prot in URI with large POST data
- Unusual outbound connections from router to external IPs
SIEM Query:
source="router_logs" AND (uri="/goform/L7Prot" OR message="buffer overflow")🔗 References
- https://github.com/zezhifu1/cve_report/blob/main/FH451/frmL7ProtForm.md
- https://github.com/zezhifu1/cve_report/blob/main/FH451/frmL7ProtForm.md#payload
- https://vuldb.com/?ctiid.316188
- https://vuldb.com/?id.316188
- https://vuldb.com/?submit.611504
- https://www.tenda.com.cn/
- https://github.com/zezhifu1/cve_report/blob/main/FH451/frmL7ProtForm.md
- https://github.com/zezhifu1/cve_report/blob/main/FH451/frmL7ProtForm.md#payload
