CVE-2025-29361
📋 TL;DR
A buffer overflow vulnerability in Tenda RX3 routers allows attackers to cause denial of service via specially crafted packets sent to the /goform/SetVirtualServerCfg endpoint. This affects Tenda RX3 router users running vulnerable firmware versions. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- Tenda RX3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reset, potential for remote code execution if buffer overflow can be controlled precisely
Likely Case
Router becomes unresponsive requiring reboot, disrupting network connectivity for all connected devices
If Mitigated
Minimal impact if router is behind firewall with restricted WAN access
🎯 Exploit Status
Exploitation requires crafting specific HTTP requests to the vulnerable endpoint
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Tenda website for firmware updates beyond V16.03.13.11
Vendor Advisory: Not provided in references
Restart Required: Yes
Instructions:
1. Log into router admin interface 2. Navigate to firmware update section 3. Download latest firmware from Tenda website 4. Upload and apply update 5. Reboot router
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router management interface
Restrict management interface access
allUse firewall rules to limit access to router management IP/port
🧯 If You Can't Patch
- Place router behind additional firewall with strict inbound rules
- Disable UPnP and port forwarding features if not needed
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface matches vulnerable versionCheck Version:
Check via router web interface or SSH if enabledVerify Fix Applied:
Verify firmware version has been updated to patched version📡 Detection & Monitoring
Log Indicators:
- Multiple failed HTTP POST requests to /goform/SetVirtualServerCfg
- Router reboot events in system logs
Network Indicators:
- Unusual HTTP traffic to router management port (typically 80/443)
- Router becoming unresponsive to ping
SIEM Query:
source_ip="router_ip" AND (url_path="/goform/SetVirtualServerCfg" OR event_type="system_reboot")