CVE-2025-50647 Overview
A buffer overflow vulnerability exists in D-Link DI-8003 firmware version 16.07.26A1, specifically in the handling of the wans parameter in the qos.asp endpoint. This firmware vulnerability affects the network router's web management interface and could allow attackers to corrupt memory by supplying malicious input to the vulnerable parameter.
Critical Impact
Successful exploitation of this buffer overflow vulnerability could allow an attacker to corrupt memory, potentially leading to denial of service or arbitrary code execution on the affected D-Link router.
Affected Products
- D-Link DI-8003 firmware version 16.07.26A1
Discovery Timeline
- April 8, 2026 - CVE-2025-50647 published to NVD
- April 8, 2026 - Last updated in NVD database
Technical Details for CVE-2025-50647
Vulnerability Analysis
This buffer overflow vulnerability resides in the qos.asp endpoint of the D-Link DI-8003 router's web management interface. The vulnerability occurs when the firmware processes the wans parameter without proper bounds checking. When an attacker supplies an overly long or specially crafted value to this parameter, the firmware fails to validate the input length before copying it into a fixed-size memory buffer.
Buffer overflows in embedded network 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. This makes exploitation more reliable and increases the potential impact of the vulnerability.
Root Cause
The root cause of this vulnerability is improper input validation in the firmware's handling of the wans parameter within the qos.asp quality-of-service configuration page. The firmware does not adequately verify the length of user-supplied input before performing memory copy operations, allowing data to overflow beyond the allocated buffer boundaries.
Attack Vector
An attacker with network access to the router's web management interface could exploit this vulnerability by sending a crafted HTTP request containing an oversized or malicious wans parameter to the qos.asp endpoint. The attack requires the web management interface to be accessible, which may be limited to the local network by default, but could be exposed if remote management is enabled.
The exploitation would typically involve:
- Identifying a D-Link DI-8003 router running the vulnerable firmware version
- Accessing the web management interface (typically on port 80 or 443)
- Sending a specially crafted request to the qos.asp endpoint with a malformed wans parameter
- The malformed input overflows the buffer, potentially corrupting adjacent memory structures
For technical details on the vulnerability mechanism, refer to the GitHub IoT Vulnerability Collection and the D-Link Security Bulletin.
Detection Methods for CVE-2025-50647
Indicators of Compromise
- Unexpected router reboots or crashes when accessing QoS configuration pages
- Abnormal HTTP requests to qos.asp with unusually long parameter values
- Router becoming unresponsive after web management interface access
- Unusual network traffic patterns from the router's management interface
Detection Strategies
- Monitor HTTP traffic to the router's web management interface for requests containing abnormally large wans parameter values
- Implement network intrusion detection rules to identify oversized POST/GET requests to qos.asp
- Review router logs for repeated crashes or service restarts correlated with web interface access
- Deploy firmware version scanning to identify routers running vulnerable 16.07.26A1 firmware
Monitoring Recommendations
- Enable logging on network segments containing D-Link DI-8003 devices
- Configure SIEM alerts for anomalous traffic patterns targeting router management interfaces
- Regularly audit firmware versions across all network infrastructure devices
- Monitor for unexpected outbound connections from router devices that may indicate compromise
How to Mitigate CVE-2025-50647
Immediate Actions Required
- Restrict access to the router's web management interface to trusted IP addresses only
- Disable remote management if not required for operational purposes
- Place the router behind a firewall that filters management interface traffic
- Consider network segmentation to isolate management interfaces from general network traffic
- Check the D-Link Security Bulletin for firmware updates
Patch Information
Consult the D-Link Security Bulletin for official patch availability and firmware update instructions. Ensure the router is updated to the latest available firmware version that addresses this buffer overflow vulnerability.
Workarounds
- Disable the web management interface if not required and use console/CLI access instead
- Implement access control lists (ACLs) to restrict management interface access to specific administrator IP addresses
- Enable HTTPS for the management interface and disable HTTP to reduce attack surface
- Deploy a web application firewall (WAF) in front of the management interface to filter malicious requests
Configuration to restrict management interface access (example for upstream firewall):
# Example iptables rules to restrict access to router management interface
# Replace ROUTER_IP with your D-Link DI-8003 IP address
# Replace ADMIN_IP with trusted administrator IP address
iptables -A FORWARD -d ROUTER_IP -p tcp --dport 80 -s ADMIN_IP -j ACCEPT
iptables -A FORWARD -d ROUTER_IP -p tcp --dport 443 -s ADMIN_IP -j ACCEPT
iptables -A FORWARD -d ROUTER_IP -p tcp --dport 80 -j DROP
iptables -A FORWARD -d ROUTER_IP -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
