CVE-2025-6393
📋 TL;DR
This critical buffer overflow vulnerability in TOTOLINK routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the /boafrm/formIPv6Addr endpoint. Attackers can exploit this without authentication to potentially take full control of affected devices. Users of TOTOLINK A702R, A3002R, A3002RU, and EX1200T routers with vulnerable firmware versions are affected.
💻 Affected Systems
- TOTOLINK A702R
- TOTOLINK A3002R
- TOTOLINK A3002RU
- TOTOLINK EX1200T
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, network traffic interception, and lateral movement to other network devices.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a botnet node.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering or in isolated network segments.
🎯 Exploit Status
Public exploit code is available in GitHub repositories. The attack requires sending a crafted HTTP POST request with malicious data in the submit-url parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check TOTOLINK website for firmware updates. 2. Download latest firmware for your model. 3. Access router web interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router after update.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the router's web management interface to prevent HTTP-based exploitation.
Access router CLI via SSH/Telnet
Navigate to management settings
Disable web interface
Restrict Management Access
linuxConfigure firewall rules to only allow management access from trusted IP addresses.
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLANs with strict network segmentation
- Implement network monitoring for suspicious HTTP POST requests to /boafrm/formIPv6Addr
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface (Status > Device Info) or SSH command: cat /proc/versionCheck Version:
cat /proc/version or check web interface Status pageVerify Fix Applied:
Verify firmware version has been updated to a version not listed in affected versions📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /boafrm/formIPv6Addr with unusually long submit-url parameters
- Router crash/restart logs following HTTP requests
Network Indicators:
- HTTP traffic to router port 80 with POST requests containing buffer overflow patterns in submit-url parameter
SIEM Query:
source="router_logs" AND uri="/boafrm/formIPv6Addr" AND method="POST" AND (param_length(submit-url) > 100 OR contains(param_value(submit-url), "\x90\x90"))🔗 References
- https://github.com/awindog/cve/blob/main/688/15.md
- https://github.com/awindog/cve/blob/main/688/16.md
- https://vuldb.com/?ctiid.313386
- https://vuldb.com/?id.313386
- https://vuldb.com/?submit.597565
- https://vuldb.com/?submit.597566
- https://vuldb.com/?submit.597591
- https://vuldb.com/?submit.597592
- https://www.totolink.net/
- https://github.com/awindog/cve/blob/main/688/15.md
