CVE-2025-7527
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda FH1202 routers allows remote attackers to execute arbitrary code by manipulating the PPPOEPassword parameter. This affects Tenda FH1202 firmware version 1.2.0.14(408) and potentially other versions. Attackers can exploit this without authentication to take full control of affected routers.
💻 Affected Systems
- Tenda FH1202
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete router compromise, enabling attackers to intercept traffic, pivot to internal networks, install persistent malware, or brick devices.
Likely Case
Remote code execution resulting in router takeover, allowing traffic interception, DNS hijacking, credential theft, and network persistence.
If Mitigated
Limited impact if routers are behind firewalls with strict ingress filtering, though internal exploitation remains possible.
🎯 Exploit Status
Public exploit details are available on GitHub, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. If an update is available, download the firmware file. 3. Log into the router's web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install the new firmware. 6. Reboot the router after installation.
🔧 Temporary Workarounds
Disable WAN Management Access
allPrevent external access to the router's management interface
Log into router web interface > Advanced > System Tools > Remote Management > Disable WAN access
Network Segmentation
allIsolate the router management interface to a dedicated VLAN
🧯 If You Can't Patch
- Replace affected routers with patched or alternative models
- Implement strict network access controls to limit access to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface: Login > System Tools > Firmware Version. If version is 1.2.0.14(408), the device is vulnerable.Check Version:
curl -s http://router-ip/goform/getStatus | grep version (if API accessible)Verify Fix Applied:
After updating firmware, verify the version number has changed from 1.2.0.14(408) to a newer version.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/AdvSetWan with long PPPOEPassword parameters
- Multiple failed login attempts followed by exploitation attempts
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- DNS queries to suspicious domains from router
SIEM Query:
source="router_logs" AND (url="/goform/AdvSetWan" AND post_data CONTAINS "PPPOEPassword")