CVE-2025-5527
📋 TL;DR
This critical vulnerability in Tenda RX3 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the SetStaticRouteCfg function. Attackers can exploit this without authentication to potentially take full control of affected devices. All users running the vulnerable firmware version are at risk.
💻 Affected Systems
- Tenda RX3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access, though internal network attacks remain possible.
🎯 Exploit Status
Exploit details are publicly disclosed on GitHub, making weaponization straightforward. No authentication required for exploitation.
🛠️ 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. Wait for router to reboot
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router web interface
Network segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected devices with patched or different vendor equipment
- Implement strict network access controls to limit traffic to router management interface
🔍 How to Verify
Check if Vulnerable:
Access router web interface, navigate to System Status or About page, check firmware version matches 16.03.13.11_multi_TDE01Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
After firmware update, verify version no longer matches vulnerable version and test SetStaticRouteCfg endpoint with safe payloads📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/SetStaticRouteCfg with large payloads
- Unusual process execution in router logs
- Configuration changes without authorized user activity
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting command and control communication
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (uri="/goform/SetStaticRouteCfg" AND content_length>1000) OR process="unexpected_binary"