CVE-2025-3259
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda RX3 routers allows remote attackers to execute arbitrary code by sending specially crafted requests to the /goform/SetOnlineDevName endpoint. This affects Tenda RX3 routers running firmware version 16.03.13.11. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- Tenda RX3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full router compromise, credential theft, network traffic interception, and lateral movement into connected networks.
Likely Case
Router takeover enabling DNS hijacking, man-in-the-middle attacks, and persistent backdoor installation.
If Mitigated
Denial of service or router crash requiring physical reset if exploit fails.
🎯 Exploit Status
Public exploit details are available, making weaponization 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 website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Tenda RX3 routers from critical networks and internet exposure
Access Control Lists
linuxBlock access to /goform/SetOnlineDevName endpoint at network perimeter
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/SetOnlineDevName" --algo bm -j DROP
🧯 If You Can't Patch
- Replace affected routers with different models that have available security updates
- Implement strict network monitoring for exploitation attempts and anomalous router behavior
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface or via telnet/ssh if enabledCheck Version:
curl -s http://router-ip/login/Auth | grep firmware version or check admin web interfaceVerify Fix Applied:
Verify firmware version is no longer 16.03.13.11 and test if /goform/SetOnlineDevName endpoint responds to buffer overflow attempts📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/SetOnlineDevName
- Router crash/reboot logs
- Large devName parameter values in web logs
Network Indicators:
- HTTP requests with oversized devName parameters
- Traffic to router on unusual ports post-exploit
- DNS queries from router to suspicious domains
SIEM Query:
source="router_logs" AND (uri="/goform/SetOnlineDevName" AND content_length>100) OR (event="crash" AND device="tenda_rx3")🔗 References
- https://sixth-action-50e.notion.site/Tenda-RX3-Buffer-Overflow-1c9f6468377380a2977cd6c3a81f453c?pvs=4
- https://vuldb.com/?ctiid.303329
- https://vuldb.com/?id.303329
- https://vuldb.com/?submit.549199
- https://www.tenda.com.cn/
- https://sixth-action-50e.notion.site/Tenda-RX3-Buffer-Overflow-1c9f6468377380a2977cd6c3a81f453c
