CVE-2025-50670: D-Link DI-8003 Buffer Overflow Vulnerability

CVE-2025-50670 Overview

A buffer overflow vulnerability exists in D-Link DI-8003 firmware version 16.07.26A1 due to improper handling of parameters in the /xwgl_bwr.asp endpoint. An attacker can exploit this vulnerability by sending a crafted HTTP GET request targeting the name, qq, and time parameters, potentially leading to arbitrary code execution or denial of service on the affected device.

Critical Impact

This buffer overflow vulnerability in D-Link DI-8003 routers could allow remote attackers to execute arbitrary code or crash the device by exploiting improper input validation in the web management interface.

Affected Products

• D-Link DI-8003 firmware version 16.07.26A1

Discovery Timeline

• 2026-04-08 - CVE-2025-50670 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2025-50670

Vulnerability Analysis

This vulnerability stems from a classic buffer overflow condition in the D-Link DI-8003 router's web management interface. The /xwgl_bwr.asp endpoint fails to properly validate the length of user-supplied input in the name, qq, and time parameters before copying them into fixed-size memory buffers. When an attacker provides oversized input values, the data overflows the allocated buffer boundaries, potentially overwriting adjacent memory regions including return addresses and function pointers.

The vulnerability is particularly concerning as it affects the router's web interface, which may be accessible from the local network or, in misconfigured environments, from the internet. Successful exploitation could allow an attacker to gain control of the device, intercept network traffic, or use the compromised router as a pivot point for further attacks on the internal network.

Root Cause

The root cause of this vulnerability is improper input validation and the absence of boundary checks when handling HTTP GET request parameters. The firmware fails to verify that the length of user-supplied strings in the name, qq, and time parameters does not exceed the size of the destination buffers. This is a common vulnerability pattern in embedded device firmware, often resulting from the use of unsafe string handling functions such as strcpy() or sprintf() without proper length validation.

Attack Vector

An attacker can exploit this vulnerability remotely by sending a specially crafted HTTP GET request to the vulnerable /xwgl_bwr.asp endpoint. The attack requires network access to the device's web management interface. By manipulating the name, qq, or time parameters with maliciously long strings, an attacker can trigger the buffer overflow condition. Depending on the memory layout and protections in place, this could lead to arbitrary code execution, denial of service, or information disclosure.

The attack does not require authentication if the web interface is accessible, making it particularly dangerous in environments where the management interface is exposed to untrusted networks.

Detection Methods for CVE-2025-50670

Indicators of Compromise

• Unusual HTTP GET requests to /xwgl_bwr.asp containing excessively long parameter values
• Device crashes, unexpected reboots, or unresponsive web management interface
• Anomalous network traffic patterns originating from the D-Link DI-8003 device
• Unauthorized configuration changes or new administrative accounts on the device

Detection Strategies

• Monitor web server logs for requests to /xwgl_bwr.asp with abnormally large name, qq, or time parameter values
• Implement network-based intrusion detection rules to identify buffer overflow exploitation attempts targeting D-Link devices
• Deploy endpoint detection solutions capable of monitoring embedded device behavior for signs of memory corruption
• Conduct regular vulnerability scans of network infrastructure to identify affected firmware versions

Monitoring Recommendations

• Enable detailed logging on network firewalls for traffic directed at D-Link device management interfaces
• Set up alerts for HTTP requests containing parameter values exceeding typical length thresholds
• Monitor device health metrics such as uptime, memory usage, and CPU utilization for anomalies
• Implement network segmentation to limit exposure of vulnerable devices

How to Mitigate CVE-2025-50670

Immediate Actions Required

• Restrict access to the D-Link DI-8003 web management interface to trusted networks only
• Implement firewall rules to block external access to the device's management ports
• Consider disabling the web management interface if not required for operations
• Upgrade to a patched firmware version when available from D-Link

Patch Information

Users should monitor the D-Link Security Bulletin for firmware updates addressing this vulnerability. Additional technical details may be available in the GitHub IoT Vulnerability Collection. As of the publication date, users are advised to apply compensating controls until an official patch is released.

Workarounds

• Restrict network access to the router's web interface using firewall rules or access control lists (ACLs)
• Place the D-Link DI-8003 behind a separate firewall that can filter malicious requests
• Disable remote management features and allow only local console access when possible
• Implement network-level intrusion prevention to block known buffer overflow attack patterns

# Example firewall rule to restrict management interface access (iptables)
# Block external access to web management port (adjust port number as needed)
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP