CVE-2025-6825
📋 TL;DR
A critical buffer overflow vulnerability in TOTOLINK A702R routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the /boafrm/formWlSiteSurvey endpoint. This affects all users running firmware versions up to 4.0.0-B20230721.1521, potentially leading to complete device compromise.
💻 Affected Systems
- TOTOLINK A702R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full router compromise, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Router takeover enabling traffic interception, DNS manipulation, and lateral movement into connected networks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access, though internal attacks remain possible.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None known
Restart Required: No
Instructions:
Check TOTOLINK website for firmware updates. If available, download latest firmware and apply via web interface System Tools > Firmware Upgrade.
🔧 Temporary Workarounds
Disable WAN Access to Web Interface
linuxBlock external access to router management interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Restrict Management Interface Access
linuxLimit web interface access to specific trusted IP addresses only
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Replace vulnerable router with supported model
- Place router behind dedicated firewall with strict inbound rules
🔍 How to Verify
Check if Vulnerable:
Check firmware version in web interface: Login > System Tools > Firmware Upgrade. Version should be higher than 4.0.0-B20230721.1521.Check Version:
curl -s http://router-ip/ | grep -i firmware || ssh admin@router-ip 'cat /etc/version'Verify Fix Applied:
Verify firmware version is updated and test with known exploit payloads (use caution).📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /boafrm/formWlSiteSurvey with long submit-url parameter
- Router crash/reboot logs
- Unusual process execution in system logs
Network Indicators:
- HTTP traffic to router IP on port 80/443 with POST to vulnerable endpoint
- Unusual outbound connections from router
SIEM Query:
source="router-logs" AND (url="/boafrm/formWlSiteSurvey" OR "submit-url" AND content_length>1000)🔗 References
- https://github.com/awindog/cve/blob/main/688/29.md
- https://github.com/awindog/cve/blob/main/688/29.md#poc
- https://vuldb.com/?ctiid.314263
- https://vuldb.com/?id.314263
- https://vuldb.com/?submit.602655
- https://www.totolink.net/
- https://github.com/awindog/cve/blob/main/688/29.md
- https://github.com/awindog/cve/blob/main/688/29.md#poc
