CVE-2025-7790 – This critical vulnerability in D-Link DI-8100 r... (How to Fix)

Q: What is the severity of CVE-2025-7790?

CVE-2025-7790 has a CVSS score of 8.8 (HIGH). This critical vulnerability in D-Link DI-8100 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the HTTP Request Handler when manipulating specific arguments in the /menu_nat.asp file. Attackers can exploit this without authentication to potentially take full control of affected devices. Organizations using D-Link DI-8100 routers with vulnerable firmware are at risk.

📋 TL;DR

This critical vulnerability in D-Link DI-8100 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the HTTP Request Handler when manipulating specific arguments in the /menu_nat.asp file. Attackers can exploit this without authentication to potentially take full control of affected devices. Organizations using D-Link DI-8100 routers with vulnerable firmware are at risk.

💻 Affected Systems

Products:

D-Link DI-8100

Versions: 16.07.26A1

Operating Systems: Embedded router firmware

Default Config Vulnerable: ⚠️ Yes

Notes: Affects the web management interface component. Devices with web interface exposed are vulnerable.

📦 What is this software?

Di 8100 Firmware by Dlink

View all CVEs affecting Di 8100 Firmware →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete device compromise, lateral movement into internal networks, persistent backdoor installation, and data exfiltration.

🟠

Likely Case

Device takeover enabling network traffic interception, credential theft, and use as pivot point for further attacks.

🟢

If Mitigated

Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.

🌐 Internet-Facing: HIGH - Exploitable remotely without authentication, making internet-exposed devices immediate targets.

🏢 Internal Only: MEDIUM - Internal devices still vulnerable to compromised internal hosts or attackers who breach perimeter defenses.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Public exploit code exists in GitHub repository. Attack requires sending specially crafted HTTP requests to the vulnerable endpoint.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Unknown

Vendor Advisory: https://www.dlink.com/

Restart Required: Yes

Instructions:

1. Check D-Link website for firmware updates. 2. Download latest firmware for DI-8100. 3. Upload via web interface. 4. Reboot router after update.

🔧 Temporary Workarounds

Disable Web Management Interface

all

Disable the web management interface if not required for operations

Access router CLI via SSH/Telnet
Disable HTTP/HTTPS services in configuration

Restrict Web Interface Access

all

Limit web interface access to specific management IP addresses only

Configure firewall rules to allow only trusted IPs to port 80/443

🧯 If You Can't Patch

Segment affected routers in isolated network zones with strict firewall rules
Implement network monitoring for unusual HTTP requests to /menu_nat.asp

🔍 How to Verify

Check if Vulnerable:

Check firmware version via web interface: Login > System > Firmware Information. If version is 16.07.26A1, device is vulnerable.

Check Version:

curl -k https://[router-ip]/getcfg.php | grep version

Verify Fix Applied:

Verify firmware version has changed from 16.07.26A1 to a newer version after update.

📡 Detection & Monitoring

Log Indicators:

Multiple HTTP POST requests to /menu_nat.asp with long parameter values
Unusual outbound connections from router to external IPs

Network Indicators:

HTTP requests with abnormally long out_addr/in_addr/out_port/proto parameters
Traffic patterns suggesting router compromise

SIEM Query:

source="router_logs" AND uri="/menu_nat.asp" AND (param_length>1000 OR status_code=500)

📊 Metadata

CVE ID: CVE-2025-7790

CVSS v3 Score: 8.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-119

EPSS Score: 0.14% exploit probability (34th percentile)

Published: July 18, 2025

Last Updated: July 23, 2025

🔗 References

https://github.com/XiDP0/MyCVE/blob/main/CVE/D-Link%20DI_8100-16.07.26A1/menu_nat_asp/menu_nat_asp.md Exploit,Third Party Advisory
https://vuldb.com/?ctiid.316851 Permissions Required
https://vuldb.com/?id.316851 Third Party Advisory,VDB Entry
https://vuldb.com/?submit.616196 Third Party Advisory,VDB Entry
https://www.dlink.com/ Product
https://github.com/XiDP0/MyCVE/blob/main/CVE/D-Link%20DI_8100-16.07.26A1/menu_nat_asp/menu_nat_asp.md Exploit,Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2025-7790, you might also want to check these: