CVE-2026-3815
📋 TL;DR
A buffer overflow vulnerability in UTT HiPER 810G routers allows remote attackers to execute arbitrary code by exploiting the strcpy function in the /goform/formApMail endpoint. This affects all versions up to 1.7.7-1711. Attackers can compromise the router remotely without authentication.
💻 Affected Systems
- UTT HiPER 810G
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise leading to persistent backdoor installation, network traffic interception, lateral movement to internal networks, and device bricking.
Likely Case
Router takeover enabling man-in-the-middle attacks, credential theft, DNS hijacking, and botnet recruitment.
If Mitigated
Limited impact if network segmentation isolates the router and external access is restricted, though local network attacks remain possible.
🎯 Exploit Status
Public exploit code is available on GitHub, making exploitation trivial for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory found in provided references
Restart Required: Yes
Instructions:
1. Check vendor website for firmware updates
2. If update available, download and verify checksum
3. Backup current configuration
4. Upload new firmware via web interface
5. Reboot router
6. Restore configuration if needed
🔧 Temporary Workarounds
Block External Access
linuxPrevent external exploitation by blocking WAN access to router management interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Vulnerable Endpoint
linuxBlock access to the vulnerable /goform/formApMail endpoint if possible
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/formApMail" --algo bm -j DROP
🧯 If You Can't Patch
- Segment router on isolated network VLAN to limit lateral movement
- Implement strict firewall rules to allow only necessary traffic to/from router
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface at System > Firmware Upgrade or via SSH with 'cat /proc/version'Check Version:
curl -s http://router-ip/ | grep -i 'version' || ssh admin@router-ip 'cat /proc/version'Verify Fix Applied:
Verify firmware version is above 1.7.7-1711 and test if /goform/formApMail endpoint still exists📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/formApMail with long parameters
- Unusual process execution in router logs
- Configuration changes without authorization
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting man-in-the-middle
- DNS queries to suspicious domains
SIEM Query:
source="router_logs" AND (url="/goform/formApMail" AND content_length>1000) OR (process="malicious_binary")