CVE-2025-57637
📋 TL;DR
A buffer overflow vulnerability in D-Link DI-7100G routers allows attackers to execute arbitrary code or cause denial of service by exploiting the viav4 parameter in the jhttpd service. This affects organizations using these routers, particularly those with internet-facing deployments. Attackers can potentially gain full control of affected devices.
💻 Affected Systems
- D-Link DI-7100G
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, lateral movement into internal networks, and persistent backdoor installation.
Likely Case
Denial of service causing router crashes and network disruption, with potential for limited code execution in constrained environments.
If Mitigated
Minimal impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
The GitHub reference contains technical details that could facilitate exploitation. Buffer overflow vulnerabilities in embedded devices are commonly weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Check D-Link security bulletin for firmware updates. 2. Download latest firmware from D-Link support site. 3. Upload firmware via web interface. 4. Reboot router after update completes.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the vulnerable jhttpd service
Access router web interface > Management > Remote Management > Disable
Network Segmentation
linuxIsolate router management interface from untrusted networks
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Place device behind firewall with strict inbound filtering on ports 80/443
- Implement network segmentation to isolate router from critical internal assets
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System > Firmware. If version is 2020-02-21, device is vulnerable.Check Version:
curl -s http://router-ip/status.html | grep FirmwareVerify Fix Applied:
Verify firmware version has changed from 2020-02-21 to a newer version after update.📡 Detection & Monitoring
Log Indicators:
- Multiple connection attempts to port 80/443 with malformed viav4 parameters
- Router crash/restart logs
- Unusual process execution in system logs
Network Indicators:
- HTTP requests with unusually long viav4 parameters
- Traffic patterns suggesting buffer overflow attempts
- Unexpected outbound connections from router
SIEM Query:
source="router_logs" AND ("viav4" AND length>100) OR "jhttpd crash"