CVE-2025-50662: D-Link DI-8003 Buffer Overflow Vulnerability

CVE-2025-50662 Overview

A buffer overflow vulnerability has been identified in D-Link DI-8003 firmware version 16.07.26A1. The vulnerability exists due to improper handling of the name parameter in the /url_group.asp endpoint. This flaw allows attackers to potentially overflow a buffer by sending specially crafted input, which could lead to denial of service or potentially arbitrary code execution on affected devices.

Critical Impact

Network-accessible D-Link DI-8003 routers running vulnerable firmware are exposed to buffer overflow attacks that could compromise device integrity and network security.

Affected Products

• D-Link DI-8003 firmware version 16.07.26A1
• D-Link DI-8003 devices with unpatched firmware

Discovery Timeline

• 2026-04-08 - CVE-2025-50662 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2025-50662

Vulnerability Analysis

This buffer overflow vulnerability arises from insufficient bounds checking when the D-Link DI-8003 router processes the name parameter submitted to the /url_group.asp endpoint. When a user or attacker submits data to this endpoint, the firmware fails to properly validate the length of the input before copying it into a fixed-size buffer in memory.

Buffer overflow vulnerabilities in embedded devices like routers are particularly concerning because these devices often lack modern memory protection mechanisms such as ASLR (Address Space Layout Randomization) or stack canaries that are common in desktop operating systems. This makes exploitation more reliable and increases the risk of successful attacks.

Root Cause

The root cause of this vulnerability is improper input validation in the web management interface of the D-Link DI-8003 router. The /url_group.asp endpoint accepts a name parameter without enforcing adequate length restrictions. When an oversized string is passed to this parameter, it can overflow the destination buffer, potentially overwriting adjacent memory regions including return addresses or function pointers.

Attack Vector

An attacker with network access to the D-Link DI-8003 administrative interface can exploit this vulnerability by sending a maliciously crafted HTTP request to the /url_group.asp endpoint with an excessively long name parameter value. If the management interface is exposed to the internet or an attacker gains access to the local network, they can trigger the buffer overflow.

The exploitation mechanism involves submitting a specially crafted request to the vulnerable endpoint where the name parameter contains data exceeding the expected buffer size. This can corrupt memory structures and potentially allow the attacker to control program execution flow. For technical details regarding this vulnerability, refer to the GitHub IoT Vulnerability Collection.

Detection Methods for CVE-2025-50662

Indicators of Compromise

• Abnormally long HTTP requests to /url_group.asp with oversized name parameter values
• Unexpected router reboots or crashes that may indicate exploitation attempts
• Unusual network traffic patterns originating from or targeting the router management interface
• Modified router configurations or unauthorized administrative access

Detection Strategies

• Monitor HTTP request logs for requests to /url_group.asp with name parameters exceeding normal length thresholds
• Deploy network-based intrusion detection rules to identify buffer overflow attack patterns targeting D-Link devices
• Implement web application firewall rules to block excessively long parameter values to router management interfaces
• Use firmware integrity checking tools to detect unauthorized modifications to router firmware

Monitoring Recommendations

• Enable logging on the D-Link DI-8003 management interface and forward logs to a centralized SIEM system
• Configure network monitoring to alert on suspicious traffic patterns to router administrative ports
• Regularly audit network device configurations for unauthorized changes
• Monitor for D-Link security bulletins at the D-Link Security Bulletin page

How to Mitigate CVE-2025-50662

Immediate Actions Required

• Restrict access to the D-Link DI-8003 management interface to trusted IP addresses only
• Disable remote management access if not required for operations
• Implement network segmentation to isolate affected devices from untrusted networks
• Consider replacing end-of-life D-Link devices with supported alternatives

Patch Information

Check the D-Link Security Bulletin for official firmware updates addressing this vulnerability. As the D-Link DI-8003 may be an end-of-life product, firmware patches may not be available. Organizations should verify the support status of their devices and consider hardware replacement if patches are not forthcoming.

Workarounds

• Configure firewall rules to block external access to the router management interface (typically ports 80/443)
• Implement access control lists (ACLs) on the router to restrict management access to specific internal IP addresses
• Use a VPN for remote administration instead of exposing the management interface directly
• Deploy a network-based IPS with signatures for buffer overflow attacks targeting embedded devices

# Example firewall rule to restrict management access (iptables)
# Block external access to router management on port 80
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP

# Allow only specific management IP
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP